Author Topic: Pd/quinone patents  (Read 3517 times)

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PolytheneSam

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Pd/quinone patents
« on: December 15, 2002, 02:12:00 AM »
These two patents discuss Wacker/Wacker-like reactions which may include the use of quinones as co-catalyst.

Patent US5710342

quinones

Patent US3076032

quinones col 3

http://www.geocities.com/dritte123/PSPF.html


The hardest thing to explain is the obvious

PolytheneSam

  • Guest
two more
« Reply #1 on: December 17, 2002, 12:48:00 AM »

Patent US3365499

examples with quinones

Patent US3927111

quinones and other oxidizing agents Col. 2 L. 12+; Col. 9 L. 17+

http://www.geocities.com/dritte123/PSPF.html


The hardest thing to explain is the obvious

SPISSHAK

  • Guest
U.S. patent 3365499 is the best patent out the ...
« Reply #2 on: December 19, 2002, 01:41:00 AM »
U.S. patent 3365499 is the best patent out the whole lot.
It's worth some investigation, they describe a process of using an aprotic solvent with high dielectric constant (dimethylformamide, and dmso) and titrating the reaction with water as you go with the olefin dumped in wholesale, instead of vice versa.
This affects yeild because in a typical benzoquinone wacker system copiuos amounts of water are used (for a wacker system) and water interferes with the Pd+2 coordinating to the alkene of interest.
This improves yeilds 15% or more, good find Sam!
Another improvement is the conditions can be done where the solution is kept closer to ambient tempertures which in my opinion will produce a cleaner product.One thing to scrutinize in these examples are that such a large amount of Palladium was used in relation to the alkene it makes me wonder if this variable was tweeked to proove an invalid case.
One thing to consider if you were to use more realistic amounts of Palladium in relation to the alkene, would be the rate of addition of water, as it would recycle more slowly you may need to slow down the rate of addition.



PolytheneSam

  • Guest
These patents look interesting
« Reply #3 on: January 02, 2003, 03:39:00 AM »

Patent US2864865

note the strange quinoid compound in column 3

Patent US2035502

oxidation of p-aminophenol

Patent US3642902

pi-allyl palladium complex

See also

Post 386678

(PolytheneSam: "Wacker patents", Novel Discourse)



PolytheneSam

  • Guest
Here's a patent related to US 3642902 on the...
« Reply #4 on: January 21, 2003, 01:59:00 AM »
Here's a patent related to US 3642902 on the preparation of pi-allyl palladium complexes:

Patent US3584020



Some interesting patents that give one or both as references are:

Patent US4083874


Patent US4091019


Patent US4632996


Patent US4956496


Patent US5164518



US 4091019 mentions some palladium compounds with "tetrakis" in their names in column 2.  I've seen something like that somewhere.  See the following for a possible explanation of the meaning:

http://www.georgehart.com/virtual-polyhedra/naming.html





PolytheneSam

  • Guest
More
« Reply #5 on: January 22, 2003, 02:34:00 AM »

Patent US3370073

This one gives benzoquinone and O2 (PdCl2/CuCl2) Wacker examples with solvents like DMF, methanol, ethanol and dimethylacetamide.

Patent US3318891

palladium diacetate preparation


Bubbleplate

  • Guest
Has Anyone Tried a "Modified" Wacker
« Reply #6 on: January 24, 2003, 03:33:00 AM »
ala U.S. patent 3365499? This would be combining the PdCl2, Benzoquinone, and Safrole together upfront, then tirating with H2O over a few hours.
I'm guessing that combining everything together initially would  make for only a slightly exothermic reaction, at least until H2O is added. Am I wrong here?

Aurelius

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US Patent 4083874 Pi-Allyl Pd complexes
« Reply #7 on: February 06, 2003, 10:42:00 PM »

Patent US40838374



Process for production of allylamines from Pi-allyl palladium complexes

Abstract:

The present invention provides a process for the production of allylic amines which comprises reacting a pi-allyl palladium complex with ammonia or an amine having a reactive hydrogen attached to the nitrogen atom and a cupric salt, the reaction taking place at a temperature below the decomposition temperature of the complex and in solution in a solvent for the pi-allyl palladium complex.

References Cited:

Patent US3584020


Patent US3642902


Patent US3719701


Patent US3855321



Other References:

Akermark et al., "Tetrahedron Letters", No. 43, pp. 3733-3736, (1975).
Kuran et al., "Journal of Organometallic Chemistry", vol. 40, pp. 647-648, (1972).


Example 1:

This Example describes the effect of a copper salt on the formation of triallylamine by the process of the invention.

Allyl palladium chloride was placed in a reaction vessel provided with means for heating and for the introduction of gases.

15 Ml of dimethylacetamide were then introduced into the reaction vessel which was then pressurized to a pressure of between 6.7 and 9.5 kg/cm.sup.2 of ammonia at the reaction temperature. The reaction was conducted at the temperature indicated for an hour after which the contents of the reaction vessel were analyzed. The results are indicated below in Table I:
    ______________________________________
    Moles    Moles        Relative Amounts
    CuX.sub.2
             C.sub.3 H.sub.5 PdX
                          (C.sub.3 H.sub.5) .sub.3 N*
                                       Temp. .degree. C.
    ______________________________________
    0        0.004 C.sub.3 H.sub.5 PdCl
                           1           100
    0.008 CuCl.sub.2
             0.002 C.sub.3 H.sub.5 PdCl
                          71           100
    0.008 CuBr.sub.2
             0.004 C.sub.3 H.sub.5 PdBr
                          78           100
    ______________________________________
     *This column is a measure of the amount of the triallylamine formed in the reaction and hence a measure of the completeness of the reaction. The figure quoted is the height of a chromatogram registering the amount of the triallylamine.


The information presented in the table shows that the addition of cupric chloride or cupric bromide greatly increases the amount of triallylamine registered by the chromatograph and by inference since the tri-allylamine is formed along with diallylamine and monoallylamine, the total amount of allylamine produced.

A similar reaction but of course without the presence of cupric chloride gives a yield of only 28% of triallylamine under comparable conditions.

Example 2:

Ammonia (200 Millimoles) was added at 25.degree. C. to a solution of 3.66g (20 millimoles) of pi-allyl palladium chloride and 2.69g (20 millimoles) of cupric chloride in 80 ml of pyridine contained in an autoclave. The mixture was heated at 100.degree. C for 11/4 hours. A total yield of 61% of allylamines was obtained and of this 7 millimoles (35% of the total) was monoallylamine.

Example 3:

Example II was repeated with the solvent changed from pyridine to a mixture of N-methylpyrrolidone (45ml) and benzonitrile (35 ml). The total yield of allylamines was 47%.

Example 4:

Example III was repeated with the difference that the amount of CuCl.sub.2 was increased to 40 millimoles. The total yield of allylamines was 75%.

Example 5:

A flask was charged with 0.92g (5 millimoles) of C.sub.3 H.sub.5 PdCl.sub.2, 1.49g (11 millimoles) CuCl.sub.2 and 11 ml of N-methylpyrrolidone and 9 ml of benzonitrile. After stirring 20 minutes at room temperature, 6.5 ml (75 millimoles) of morpholine were added. In ten minutes the yield of allylmorpholene was 87%.

Examples 6-10:

The following Examples show the effect various solvents, all run under similar conditions. An autoclave was charged with 20 millimoles of C.sub.3 H.sub.5 PdCl.sub.2, 40 millimoles cupric chloride and 80 ml of solvent. After charging with ammonia the autoclave was brought to 100.degree. and samples at intervals. "Time zero" is taken to be the time when the autoclave reaches 100.degree.EXAMPLES C. and is in fact several minutes after the reactants were first mixed.
    __________________________________________________________________________
                      NH.sub.3 pressure
                             Yield of total allylamines
    Example
           solvent    kg/cu.sub.2
                             Time Zero
                                    One Hour
    __________________________________________________________________________
    VI   N-methylpyrrolidone
                      10.6   27%    77%
    VII  dimethylsulfoxide
                      11.5   20%    89%
    VIII hexamethylphosphoramide
                      10.9    4%    69%
    IX   phenylacetontrile
                      8.08   23%    49%
    X    dimethylacetamide
                      10.8   17%    67%
    __________________________________________________________________________


Examples 11-24:

The following Examples show the effect of the addition of ligands to the system. The autoclave was charged with 20 millimoles of C.sub.3 H.sub.5 PdCl.sub.2, 20 millimoles of the ligand, 40 millimoles cupric chloride and 80 ml N-methylpyrrolidone. After charging with NH.sub.3 the reactor was heated to 100.degree.. Sampling was done as in Examples VI to X.
    __________________________________________________________________________
                      NH.sub.3 pressure
                             Yield of total allylamines
    Example
           Ligand     kg/cm.sub.2
                             Time   One Hoar
    __________________________________________________________________________
    I    none         10.6   27%    77%
    XII  triphenylphosphine
                      11.4   95%    same
    XIII triphenylphsophine oxide
                      10.6   10%    78%
    XIV  DIPHOS*      11.25  76%    68%
    XV   tributylphosphite
                      10.6   100%   same
    XVI  tributylphosphate 10.9
                      14%    80%
    XVII triphenylphosphite
                      9.5    83%    89%
    XVIII
         triphenylphosphate
                      10.8   10%    76%
    XIX  tributylphosphine oxide
                      11.4   13%    78%
    XX   triphenylarsine
                      10.8   66%    55%
    __________________________________________________________________________


The remaining ligands were used at a level only 1/10 the above (i.e. 2 millimoles)
    ______________________________________
    XXI    triphenylbismarsine
                            10.7     46%   71%
    XXII   triphenylbismuthene
                            10.3     41%   53%
    XXIII  triphenylstibine 10.9     74%   71%
    XXIV   tributoxystibene 10.4     34%   80%
    ______________________________________
     * bis (1,2-diphenylphosphine) ethane


Example 25:

A run similar to Example II was made with the temperature at 76.degree. C. After 4 hours the yield of allylamines was 21%. A similar run made at 164.degree. C. for 20 minutes gave a yield of 64%. These results indicate that the reaction is enhanced by elevated temperatures.

Aurelius

  • Guest
US Patent 4091019 Unsaturated Primary Amines
« Reply #8 on: February 06, 2003, 10:54:00 PM »

Patent US4091019



Preparation of unsaturated primary amines

Abstract:

A process for the production of unsaturated primary amines which comprises reacting, in the substantial absence of molecular oxygen, an amine having the formula (R.sub.1 HC=CR.sub.2 CH.sub.2)m N H (3-m), wherein m is 2 or 3 and R.sub.1 and R.sub.2 are hydrogen or C.sub.1 - C.sub.3 alkyl groups, with ammonia in the presence of a catalyst comprising palladium or platinum atoms bearing phosphorus-containing ligands, the reaction being carried out at a temperature of from 0.degree. to 250.degree. C in the presence of a solvent for the amine and the catalyst.

References Cited:

Patent US3110731


Patent US3865877



Example 1:

A 300 ml autoclave was charged with 5.8g (5 millimoles) of tetrakis (triphenylphosphine) palladium, 1.8g (13.3 millimoles) of triallylamine and 80ml of N-methyl pyrrolidone as a solvent. Oxygen was removed from the autoclave by a nitrogen purge and then ammonia was added with stirring until the internal pressure reached 3.87 Kg/cm. The reactor was then heated with stirring to 100.degree. C (pressure - 10.19 kg/cm) and subsequently to 130.degree. C (pressure - 13.34 kg/cm). At 100.degree. C the reaction was very slow but after 30 minutes at 130.degree. C the triallylamine had reacted to form 5.2 millimoles of monoallylamine and 6.6 millimoles of diallylamine.

Example 2:

Example 1 was duplicated with the difference that 2.1g (40 millimoles) of ammonium chloride were added to the autoclave and the temperature was raised only to 100.degree. C. After one hour at 100.degree. C, 8.8 millimoles of monoallylamine and 8.4 millimoles of diallylamine had been formed.

Example 3:

Example 2 was duplicated except for the use of pyridine as the solvent. After 100 minutes at 100.degree. C., 4.2 millimoles of monoallylamine and 6.6 millimoles of diallylamine had been formed.

Example 4:

An autoclave was charged with 0.58g (0.5 millimoles) of tetrakis (triphenylphosphine) palladium 1.82g (13.3 millimoles) of triallylamine, 0.11g (2 millimoles) of ammonium chloride and 80ml of 1-butanol. After a nitrogen purge to remove the oxygen, the autoclave was pressured to 3.52 kg/cm.sup.2 with ammonia. It was then heated to 100.degree. C (pressure 10.19 kg/cm.sup.2) and after 15 minutes at this temperature it was found that 11 millimoles of monoallylamine and 9 millimoles of diallylamine had been formed.

Example 5:

Example 4 was duplicated with the difference that 20 millimoles of diallylamine was substituted for triallylamine as the starting material. A sample taken when the temperature had just reached 100.degree. C showed 2.8 millimoles of monoallylamine and 2.2 millimoles of triallylamine showing that some disproportionation had occurred. After 30 minutes at 100.degree. C the sample showed 13 millimoles of monoallylamine and 3.3 millimoles of triallylamine. The triallylamine content continued to diminish with increasing time under the reaction conditions.

Example 6:

An autoclave was charged with a solution of 0.44g (0.38 millimoles) of tetrakis(triphenylphosphine) palladium and 0.12g (2.3 millimoles) of ammonium chloride in 30 ml of 1-pentanol. The autoclave was purged with nitrogen, then heated to 100.degree. C with stirring at which point 1.95g. (14.2 millimoles) of triallylamine and sufficient ammonia to maintain a pressure of 10.19 kg/cm.sup.2 were added. After 45 minutes the stirred reaction mixture comprised 3.6 millimoles of monoallylamine, 7.0 millimoles of diallylamine and 8.2 millimoles of triallylamine. After 90 minutes, the respective amounts were 7.8, 9.0 and 5.6 millimoles and after 4 hours, the amounts were 10.3, 9.2 and 4.7 millimoles respectively.

Example 7:

An autoclave was charged with a solution of 0.35g (0.28 millimoles) of tetrakis (triphenylphosphine) platinum and 0.098g (1.8 millimoles) of ammonium chloride in 25 ml of 1-pentanol. The autoclave was purged with nitrogen then the mixture was heated with stirring to 100.degree. C at which point 1.5g (10.9 millimoles) of triallylamine and sufficient ammonia to maintain a pressure of 10.19 kg/cm.sup.2 were added. After 30 minutes the stirred reaction mixture comprised 5.3 millimoles of monoallylamine, 6.5 millimoles of diallylamine and 4.5 millimoles of triallylamine.

Examples 8-10:

An autoclave was charged with a solution of allyl palladium chloride and triethoxyphosphine in 80 ml of 1-pentanol. The autoclave was purged with nitrogen, then heated to 100.degree. C with stirring at which point triallylamine and sufficient ammonia to maintain a pressure of 8.08 kg/cm.sup.2 were added.

Samples of the reaction mixture were analyzed during the reaction and the results are set forth in Table 1 below.
                                      TABLE 1
    __________________________________________________________________________
     Tri AA                       Added      Reaction Mixture Analysis in
                                             Millimoles
    Example
         Charged Allyl Pd.Cl(g)
                         (EtO).sub.3 P (g)
                                  Accelerator (g)
                                             Time (mins)
                                                    Mono AA
                                                          Di
                                                              Tri
    __________________________________________________________________________
                                                              AA
    8    9.2g (67mM)
                 0.037 (0.20mM)
                         0.10 (0.62mM)
                                  --         120    6.2   14.8
                                                              54.5
                                             165    7.0   16.2
                                                              53.2
    9    9.2g (67mM)
                 0.036 (0.20mM)
                         0.97 (0.58mM)
                                  4.6g (60mM)
                                  ammonium acetate
                                             120    10.4  22.5
                                                              48.1
                                             300    17.7  30.5
                                                              40
    10   9.3g    0.036 (0.20mM)
                         .098 (0.58mM)
                                  0.11g (21.mM)
          (67.8mM)                ammonium chloride
                                             120    7.5   17.2
                                                              53.8
                                             180    10.5  23.9
                                                              48.4
    __________________________________________________________________________
     Allyl Pd Cl - allyl palladium chloride
     (EtO).sub.3 P - triethoxy phosphine
     mM - millimoles
     Tri AA - triallylamine
     Di AA - diallylamine
     Mono AA - monoallylamine


Example 11:

An autoclave was charged with a solution of 0.25g (1.34 millimoles) of allyl palladium chloride, 1.36g (5.45 millimoles) tributylphosphite, 1.92g (14.0 millimoles) of triallylamine and 0.83g (13.8 millimoles) of acetic acid in 75 ml of propylene glycol. The autoclave was then purged with nitrogen and heated to 100.degree. C with stirring at which point 9.94g (72.5 millimoles) of triallylamine were added and sufficient anhydrous ammonia to maintain a pressure of 8.08 kg/cm.sup.2. After 30 minutes of stirring at 100.degree. C, sufficient triallylamine had reacted with ammonia to give a solution of allylamines which consisted of 30 mole percent allylamine, 42 mole percent diallylamine and 28 mole percent triallylamine. After 90 minutes of stirring the mole percentages for mono-, di- and tri- allylamine were 44, 39 and 17, respectively. After 18 hours, mono-, di- and tri-allylamine molar percentages were 46, 38 16 respectively. More than 95% of the allyl groups were retained in the mixed allylamines.



Aurelius

  • Guest
US Patent 4632996 Pd Pi Bonding Chemistry
« Reply #9 on: February 06, 2003, 11:10:00 PM »

Patent US4632996



Organopalladium additions to alkenyl- and methylenecyclopropanes and alkenyl- and methylenecyclobutanes

Abstract:

(Pi-allyl)palladium compounds are prepared by organopalladium addition to alkenyl- or methylenecyclopropanes or alkenyl- or methylenecyclobutanes. The reaction is conducted in the presence of a palladium salt and involves a novel ring-opening process and a subsequent rearrangement to provide a regioselective route to (pi-allyl)palladium compounds.

References Cited:

Patent US3369035


Patent US3398168


Patent US3584020


Patent US3632824


Patent US3642902


Patent US3808246


Patent US4065479


Patent US4101566



Background of the Invention

(Pi-allyl)palladium compounds have been reported in the literature and have been found useful as chemical intermediates and catalysts. For example, such compounds have gained increasing importance as catalysts for reactions of olefins and other unsaturated organic molecules, for example in processes of oligomerization.

Although the (pi-allyl)palladium compounds have been known to be used as catalysts in the types of reactions expressed herein, there has been some difficulty in obtaining these compounds in sufficiently high quantity to make them practically available for commerical organic synthesis. This is so because (pi-allyl)palladium compounds are frequently difficult to isolate from reaction mixtures and are quite often obtained in very low yields.

In a previous patent by one of the co-inventors, Larock, U.S. Pat. No. 4,065,479, issued Dec. 27, 1977, there is disclosed a process involving vinylmercurials reacting with palladium salts and simple olefins to afford (pi-allyl)palladium compounds. This invention relates to an improvement based upon the discovery that the reaction of organomercurials, palladium salts and alkenyl- or methylenecyclopropanes and alkenyl- or methylenecyclobutanes, results in a novel ring-opening process and subsequent rearrangement which affords a valuable new regioselective route to further (pi-allyl)palladium compounds.

It is accordingly a primary objective of the present invention to provide the process and synthesis route immediately discussed above to allow the practice of a novel ring-opening process and subsequent rearrangement to prepare (pi-allyl)palladium compounds from alkenyl- or methylenecyclopropanes or alkenyl- or methylenecyclobutanes.

The method of accomplishing the above objective as well as others, including the preparation and practice of the process to yield commercially practical higher yields of product, will become apparent from the detailed description which follows hereinafter.

Summary of the Invention
 
(Pi-allyl)palladium compounds are formed via organopalladium additions to alkenyl- or methylenecyclopropanes or alkenyl- or methylenecyclobutanes by reactions with an organomercurial salt selected from the group consisting of alkyl, vinyl, aryl and heterocyclic organomercurials. The reaction involves formation of a (cycloalkylcarbinyl)palladium intermediate which undergoes ring-opening and subsequent palladium migration to provide the desired (pi-allyl)palladium products in significant yields.

Detailed Description of the Invention

Essentially this reaction involves a single pot reaction of an organomercurial, in the presence of a palladium salt, with an alkenyl- or methylenecyclopropane or an alkenyl- or methylenecyclobutane which, after formation of an intermediate cycloalkylcarbinyl palladium species, undergoes ring-opening and subsequent palladium migration to afford the end (pi-allyl)palladium product. The reaction may be represented by the following reaction scheme showing an organomercuric chloride as the organomercurial, reacting with an alkenylcyclobutane (n=1) or cyclopropane (n=0). ##STR1##

It should be understood that an organomercuric chloride is set forth as representative only. In fact, the organomercurial may be selected from those which R represents an alkyl salt, preferably C.sub.1 to C.sub.8, a vinylmercurial, an arylmercurial, preferably C.sub.6 to C.sub.18, but most preferably phenyl, and from heterocyclic C.sub.3 to C.sub.8 organomercurials. The anion of the salt is preferably a halide, preferably chloride, but may also be a nitrate, an acetate, sulfate, a phosphate, or the like, or one may use the corresponding diorganomercurials R.sub.2 Hg. In the reaction where R in the organomercurial is an alkyl group containing beta hydrogens, the product contains R.dbd.H.

As seen from the above starting equation, if n=0, the starting reactant is a cyclopropane derivative, and if n=1, it is, correspondingly, a cyclobutane derivative. It also should be understood that the reaction shows only the alkenyl scheme, but that a corresponding reaction occurs where the alkenyl moiety is replaced with a methylene moiety, with the only difference in product being the presence or absence of a methylene group in the (pi-allyl)palladium product.

The reaction is conducted in the presence of a palladium(II) salt. Most preferably this salt is palladium chloride, and it is preferred that the reaction is conducted in the presence of lithium chloride, in which case the reaction ingredient is often referred to as dilithium tetrachloropalladate having the formula: Li.sub.2 PdCl.sub.4.

In particular, the reaction with the organomercurial is conducted in the presence of a palladium salt such as lithium trichloropalladite (LiPdCl.sub.3) or dilithium tetrachloropalladate (Li.sub.2 PdCl.sub.4) with the result being transmetallation by the lithium palladium salt and addition of the resulting organopalladium intermediate to the carbon-carbon double bond of the unsaturated cyclopropane or cyclobutane.

The palladium salt employed is not critical and it may be, for example, LiPdCl.sub.3, Li.sub.2 PdCl.sub.4, PdCl.sub.2, PdCl.sub.2 coordinated with acetonitrile or benzonitrile, Pd(OAc).sub.2, or Pd(NO.sub.3).sub.2.

Pi-allylpalladium complexes are complexes in which a palladium moiety and an allylic moiety are bonded as shown below. ##STR2## The dotted line designation represents a delocalized electron system between the three indicated carbon atoms and palladium, which delocalized system is considered to at least partially donate electrons to the palladium moiety, thereby forming the pi-allyl complex. The palladium is additionally bonded to another moiety; e.g., an anion such as chloride or bromide, and these complexes are known to exist in the form of a dimer. In terms of the class of pi-allyl palladium chloride complexes, the simplest member is pi-allyl palladium chloride which is represented by the formula: ##STR3## and is given the systematic name of di-.mu.-chloro-di-pi-allyl dipalladium. Such dimers have all of the carbon and hydrogen moieties of the compound existing in a single plane, with the palladium atom sitting above the plane of the rest of the compound, along with the halogen atom. That is to say, each pi-allyl-palladium chloride molecule, for example, is associated with a second molecule sandwiched on top of it to form a dimer.

Aurelius

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more
« Reply #10 on: February 06, 2003, 11:13:00 PM »
The palladium(II) salts employed in forming the pi-allyl-palladium complexes according to the synthesis of this invention are palladium(II) salts of any of the conventional anions. They include the halides, such as chloride, bromide and iodide, sulfate, nitrate, acetate, phosphate, propionate, and others known to those skilled in the art. In summary, the precise anion of the palladium salt employed is not critical.

It is, however, preferred that the reaction be conducted in the presence of an alkali metal salt, as well as the palladium salt. The employment of an alkali metal salt in addition to the palladium salts helps in dissolving the palladium salt. Best results are obtained when the alkali metal salt is a metal halide salt such as a chloride or bromide as illustrated by sodium chloride, potassium bromide, lithium chloride, lithium bromide, and the like. Most preferably the palladium(II) salt is a palladium halide salt and a reaction equivalent amount of the salt is employed with the addition of a lithium halide salt as well. The most preferred salt is palladium chloride, and it is preferred that the reaction is conducted in the presence of lithium chloride. In this instance, the reaction ingredient is often referred to as lithium trichloropalladite or dilithium tetrachloropalladate having the formula LiPdCl.sub.3 or Li.sub.2 PdCl.sub.4. The added metal salt when one is employed may be added to the reaction mixture separately or alternatively added jointly with the palladium salt in the form of the coordination complex such as LiPdCl.sub.3 or Li.sub.2 PdCl .sub.4. In acetonitrile LiPdCl.sub.3 is the assumed reactive salt. In most of the other solvents Li.sub.2 PdCl.sub.4 is assumed to be the reactive salt.

The general procedure for conducting this reaction involves the addition of the least equivalent amounts of the organomercurial, respective cyclobutane or cyclopropane, and the palladium(II) salt. Where the olefin employed is quite volatile and quite difficult to weigh, it is preferred that two or more equivalents of the olefin are used to an equivalent amount of the organomercurial and the lithium palladium chloride salt. The reaction is preferably conducted in the presence of an organic solvent, suitable solvents being polar solvents such as tetrahydrofuran, methyl alcohol, diethyl ether, hexamethylphosphoramide, acetonitrile, and the like. Tetrahydrofuran is the preferred solvent.

The reaction is conducted under relatively mild conditions. Reaction temperatures are not critical and the reaction may be conducted at temperatures of from -20.degree. C. up to room temperature or even higher with satisfactory results. Generally 0.degree. C. has been found satisfactory, while allowing the reaction to proceed an appropriate period of time, in most cases within 15 minutes to 1 hour after the reaction has started. If desired, overnight reaction times may be employed. Suffice it to say that time is not a critical factor for the reaction of this invention.

Having now described the reaction of the invention in general terms, the following specific examples are offered to illustrate but not limit the process of the invention. Unless stated to the contrary in the table below, in each instance the general procedure involves the addition of two equivalents of olefin to an equivalent amount of the organomercurial and Li.sub.2 PdCl.sub.4 in tetrahydrofuran at 0.degree. C. The results of the experiments are set forth in tabular form below.
                                      TABLE I
    __________________________________________________________________________
    Examples 1-11
     ex-                  reaction
                                ##STR4##                          lated iso-
    am-                  con-  (.pi.-allyl)palladium compounds
                                                            compd
                                                                yield
    ple
       organomercurial
                 olefin.sup.a
                         ditions.sup.b
                               R.sup.1
                                    R.sup.2
                                       R.sup.3         R.sup.4
                                                            no..sup.c
                                                                (%)
    __________________________________________________________________________
    1  C.sub.6 H.sub.5 HgCl
                  ##STR5##
                         0.degree. C.,2h
                               CH.sub.3
                                    H  CH.sub.2 C.sub.6 H.sub.5
                                                       H    1   79
    2  CH.sub.3 HgCl     0.degree. C.,2h
                               CH.sub.3
                                    H  CH.sub.2 CH.sub.3
                                                       H    2.sup.d
                                                                52
                               CH.sub.3
                                    H  CH.sub.3        CH.sub.3
                                                            3.sup.d
    3  C.sub.2 H.sub.5 HgCl
                         0.degree. C..fwdarw.
                               CH.sub.3
                                    H  CH.sub.3        H    4   51
                         25.degree.  C.,
                         3 days
        ##STR6##         0.degree. C.,2h
                               CH.sub.3
                                    H  (E)CH.sub.2 C(CH.sub.3)CHC(CH.sub.3).su
                                       b.3             H    5   87
    5
        ##STR7##         0.degree. C.,2h
                               CH.sub.3
                                    H
                                        ##STR8##       H    6.sup.e
                                                                63
                               CH.sub.3
                                    H
                                        ##STR9##       CH.sub.3
                                                            7.sup.e,f
    6  C.sub.6 H.sub.5 HgCl
                  ##STR10##
                         0.degree. C.,2h
                               CH.sub.3 CH.sub.3
                                    CH.sub.3 CH.sub.3
                                       CH.sub.2 C.sub.6 H.sub.5 C.sub.6
                                       H.sub.5         H CH.sub.3
                                                            8.sup.g 9.sup.g
                                                                55
    7
                  ##STR11##
                         0.degree. C.,2h
                               C.sub.6 H.sub.5 CH.sub.2
                                    H  CH.sub.2 C.sub.6 H.sub.5
                                                       CH.sub.3
                                                            10  44
    8
                  ##STR12##
                         0.degree. C.,2h
                               C.sub.6 H.sub.5 CH.sub.2
                                    H  CH.sub.2 C.sub.6 H.sub.5
                                                       CH.sub.3
                                                            10  40
    9
                  ##STR13##
                         -78.degree. C..fwdarw. 0.degree. C., overnight
                               H    C.sub.6 H.sub.5
                                       CH.sub.3        H    11  24
    10
                  ##STR14##
                         0.degree. C.,18h
                               CH.sub.3 CH.sub.2 CH.sub.3 CH.sub.2
                                    H H
                                       CH.sub.2 C.sub.6 H.sub.5 CH.sub.3
                                                       CH.sub.3 CH.sub.2
                                                       C.sub.6 H.sub.5
                                                            12.sup.h 13.sup.h
                                                                80
    11
                  ##STR15##
                         0.degree. C.,18h
                               CH.sub.3 CH.sub.2
                                    H  C.sub.6 H.sub.5 H    14  70
    __________________________________________________________________________
     .sup.a Two or more (when the olefin was quite volatile and difficult to
     weigh) equiv of olefin were used in all cases.
     .sup.b All reactions were run in tetrahydrofuran.
     .sup.c All (.pi.-allyl)palladium compounds gave appropriate spectral data
     and elemental analyses.
     .sup.d Ratio of 2 to 3 is 7:1.
     .sup.e Ratio of 6 to 7 is 2:1.
     .sup.f Compound 7 is a synanti mixture.
     .sup.g Ratio of 8 to 9 is 5:1.
     .sup.h Ratio of 12 to 13 is 5:1.


As can be seen in the table that aryl, methyl, ethyl, vinyl and heterocyclic organomercurials can all be employed with equally satisfactory results. Note that the use of the ethyl mercurial gives a product of palladium hydride addition (example 3). As illustrated, a variety of olefins are observed to afford (pi-allyl)palladium compounds by this procedure. Vinylcyclopropanes of various substitution patterns can be employed. Aryl substitution of the cyclopropane ring is observed to direct ring-openings toward the aryl group (examples 7 and 8). Methylene cyclopropane also undergoes this ring-opening process (example 9). One can also use alkenyl or methylene cyclobutanes with equally good results (examples 10 and 11). Generally good yields were obtained in all cases with the exception of example 9 which may have been an aberration due to the high volatility of the olefin and its high reactivity towards lithium palladium salts.