The Vespiary

The Hive => Novel Discourse => Topic started by: Rhodium on September 11, 2003, 02:23:00 PM

Title: Oximes from Nitroalkenes using Decaborane CTH
Post by: Rhodium on September 11, 2003, 02:23:00 PM
Catalytic transfer hydrogenation of conjugated nitroalkenes using decaborane: synthesis of oximes
By S. H. Lee, Y. J. Park and C. M. Yoon

Org. Biomol. Chem. 1(7), 1099-1100 (2003) (




?,?-Unsaturated nitroalkenes are readily reduced to the corresponding aldoximes and ketoximes in good yields, using a system of decaborane (B10H14) and DMSO in methanol in the presence of 10% Pd/C at room temperature under nitrogen.
Title: Hypophosphite CTH: Nitroalkenes to Oximes
Post by: Rhodium on May 26, 2004, 06:18:00 PM
Palladium-Sodium Hypophosphite CTH: Reduction of Nitroalkenes to Oximes
Rajender S. Varma, Manju Varma and George W. Kabalka

Synthetic Communications 16(1), 91-96 (1986) (


?,?-Unsaturated nitroalkenes are readily reduced by sodium hypophosphite to the corresponding oximes in the presence of palladium.

Title: To bees with access to literature
Post by: Aurelius on May 26, 2004, 07:28:00 PM
I think a digest on Kabalka's works would be wonderful.  I know that Rhodium has access to most of his works, but it would be great if somebody else would create (at least the beginnings) a digest of his papers. 

I would do this myself, but I don't have readily accessible literature materials right now.  And it may be a few months before I do again.

Thanks to the bees for considering this request!


Title: Varma vs. Kabalka
Post by: Rhodium on May 26, 2004, 10:23:00 PM
I think a digest on Kabalka's works would be wonderful.

Not to say impossible... He's an extremely prolific author, publishing 230+ papers only between 1990-2002: (

Unfortunately a lot of his writings are rather dull, the best stuff he's done has nearly always been co-authored with Rajender S. Varma, so I believe that any digest should be on the topic of Varma's works instead. I have not found a full bibliography of his works as of yet.

Title: Varma & Kabalka: Nitroalkene Reduction Review
Post by: Rhodium on May 27, 2004, 07:48:00 PM
Selected Reductions of Conjugated Nitroalkenes
George W. Kabalka, Laila H. M. Guindi and Rajender S. Varma

Tetrahedron 46(21), 7443-7457 (1990) (


Conjugated nitroalkenes are readily reduces by a variety of borane and borohydride reagents.
The reactions provide a convenient access to a number of nitrogen and oxygen basad functional groups.

Title: Nitroalkene Synthesis & Reduction Review
Post by: Rhodium on May 30, 2004, 10:54:00 AM
Syntheses and Selected Reductions of Conjugated Nitroalkenes - A Review
George W. Kabalka & Rajender S. Varma

Org. Prep. Proced. Int. 19(4-5), 283-328 (1987) (


Table of Contents
I. Introduction
II. Preparation of Conjugated Nitroalkenes
( From Carbonyl Compounds
( From Alkenes
( Miscellaneous Methods
III. Reduction of Conjugated Nitroalkenes
( Preparation of Nitroalkanes
( Preparation of Oximes
( Preparation of Carbonyl Compounds
( Preparation of N-Substituted Hydroxylamines and Amines

I know that the layout sux somewhat, but it's really hard to place so many pictures of different sizes throughout a text without something strange happening in either Mozilla or IE...

Also, could you help me out with the reference link table? I know that at least half of the 150+ referenced articles are available on my site somewhere or here at the Hive, but not exactly where... If you can tell me which reference is found where, I'll add hyperlinks to them from within the review.)

Title: Varma&Kabalka: Cr(II) Nitrostyrene Reduction
Post by: Rhodium on June 07, 2004, 05:46:00 PM
Chromium(II) Chloride Reduction of Nitrostyrenes: A Facile Route to Oximes
Rajender S. Varma, Manju Varma and George W. Kabalka

Synthetic Communications 15(14), 1325-1332 (1985) (


?,?-Unsaturated nitroalkenes are rapidly reduced by chromium(II) chloride to oximes.
____ ___ __ _

Chromium(II) Chloride Reduction of Nitroalkenes: A Facile Route to Carbonyl Compounds
Rajender S. Varma, Manju Varma and George W. Kabalka

Tetrahedron Letters 26(32), 3777-3778 (1985) (


?,?-Unsaturated nitroalkenes are readily reduced by chromium(II) chloride to the corresponding carbonyl compounds in good yields.

This article has been posted before in

Post 244992 (

(foxy2: "Chromium(II)Chloride Reduction of Nitroalkenes", Chemistry Discourse)

Title: Nitroalkene Reactions
Post by: Rhodium on June 11, 2004, 03:30:00 AM
Conjugated nitroalkenes: versatile intermediates in organic synthesis
Anthony G. M. Barrett, Gregory G. Graboski

Chem. Rev. 86, 751-762 (1986) (

____ ___ __ _

Reactions of Sodium Borohydride in Acidic Media. V.
Reduction and Alkylation of Oximes with Carboxylic Acids; A New Synthesis of N,N-Dialkylhydroxylamines

Gribble, Gordon W.; Leiby, Robert W.; Sheehan, Myles N.

Synthesis 856-859 (1977) (

____ ___ __ _

Reduction of nitroalkenes to nitroalkanes with aqueous sodium borohydride
Albert I. Meyers, J. C. Sircar

J. Org. Chem. 32, 4134-4136 (1967) (


Title: CdCl2–Mg–H2O: Nitroalkenes to Keto-compounds
Post by: Rhodium on September 03, 2004, 09:51:00 AM
Cadmium Chloride–Magnesium–Water: A New System for Regioselective Transformation of Conjugated Nitroalkenes to Ketocompounds
Manobjyoti Bordoloi

J. Chem. Soc. Chem. Commun. 922-923 (1993) (


Reaction of 6-nitro-?5-steroids and nitroalkenes in tetrahydrofuran with CdCl2–Mg–H2O furnished 6-ketosteroids and ketocompounds, respectively, in good yield.

Title: Some of R.S.Varma's recent work's........
Post by: java on September 05, 2004, 03:25:00 PM
(Free copy available on request from:

Title: Reactions promoted by Microwaves and Clays
Post by: indole_amine on September 29, 2004, 09:02:00 PM
Clay and clay-supported reagents in organic synthesis
Rajender S. Varma
Tetrahedron 58 (2002) p.1235-1255


An overview over the possibilities and applications of different clays in organic chemistry. Solventfree reductive aminations of carbonyl compounds on clay, oxidations of alcohols to carbonyls by clayfen, conversions of aldehydes to nitriles, synthesis of imines and enamines, Friedel-Crafts, Diels-Alder, Suzuki and Heck arylation reactions can be done using clay reagents, as well as dehydrations, isomerizations and addition reactions...

Selective Nitration of Styrenes with Clayfen and Clayan: A Solvent-free Synthesis of ?-Nitrostyrenes
Varma, Rajender S.; Naicker, Kannan P.; Liesen, Per J.
Tetrahedron Letters 39, 23 (1998) pp. 3977-3980


A facile, solvent-free synthesis of beta-nitrostyrenes is described from styrene and its substituted derivatives using inexpensive "doped" clay reagents, clayfen and clayan.

Looks useful for arriving at ketones in connection with

Post 458467 (

(Rhodium: "Oximes from Nitroalkenes using Decaborane CTH", Novel Discourse)

Solid State Regeneration of Ketones from Oximes on Wet Silica Supported Sodium Periodate Using Microwaves
Varma, Rajender S.; Dahiya, Rajender; Saini, Rajesh K.
Tetrahedron Letters 38, 51 (1997) pp. 8819-8820


Microwave irradiation of ketoximes on wet silica supported sodium periodate under solvent-free conditions provides a fast, efficient and simple method for regeneration of ketones.

Clay catalyzed synthesis of imines and enamines under solvent-free conditions using microwave irradiation
(Varma, Rajender S.; Dahiya, Rajender; Kumar, Sudhir)
Tetrahedron Letters 38, 12 (1997) pp. 2039-2042


The reactions of primary and secondary amines with aldehydes and ketones, respectively, are accelereated by microwaves under solvent-free conditions in the presence of montmorillonite K 10 clay to afford a high yield synthesis of imines and enamines.

Microwave-assisted oxidation of alcohols under solvent-free conditions using clayfen
(Varma, Rajender S.; Dahiya, Rajender)
Tetrahedron Letters 38, 12 (1997) pp. 2043-2044


Adsorbed on clayfen, alcohols are readily oxidized to carbonyl compounds upon exposure to microwaves under solvent-free conditions. Tis rapid, selective and environmentally benign method conserves the use of excess solvents and toxic antioxidants usually employed.

And this transformation can also be undone... :)

Microwave-Assisted Reduction of Carbonyl Compounds in Solid State Using Sodium Borohydride Supported on Alumina
(Varma, Rajender S.; Saini, Rajesh K.)
Tetrahedron Letters 38, 25 (1997) pp. 4337-4338


A manipulatively simple and rapid method for the reduction of carbonyl compounds is described that is conducted under solventless "dry" conditions using NaBH4/alumina and microwave irradiation.