I don't have the answers you seek.
I searched my files to see what I have on that reaction and found a cool sounding Henry reaction synthesis for the microwave.

Microwave-Assisted Henry Reaction:  Solventless Synthesis of Conjugated Nitroalkenes
Rajender S. Varma,  Rajender Dahiyal, and Sudhir Kumar
Abstract: In a solventless system and under microwave irradiation, nitroaikanes react with
arylaldehydes in the presence of a catalytic amount of ammonium acetate to afford, in one step,
conjugated nitroalkenes without the isolation of intermediary ~-nitro alcohols.

Salat

Also found this from a hive archive:
KG-60-NEt2 as Henry reaction catalyst
From GC_MS, HTML by metanoid
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The following article might be interesting for some bees. It also includes the procedure to make the catalyst and references to several other interesting articles (interesting in the meaning of Henry reaction catalysts).

Use of heterogeneous catalyst KG-60-NEt2 in Michael and Henry reactions involving nitroalkanes

Tetrahedron Letters 44 (2003) 2271-2273

Abstract

The N,N-diethylpropylamine supported on amorphous silica (KG-60-NEt2) catalyses the formation of carbon_carbon bonds by nitroalkanes through both the nitroaldol (Henry) and Michael reactions. The catalyst shows general utility with a variety of electrophilic acceptors. Moreover, the catalyst can be reused for two further cycles without loss of the activity.

Article

Nitroalkanes are very important starting materials in the formation of carbon-carbon bond. The nitronate anion can react under basic conditions with saturated carbonyl compounds or with electron poor alkenes leading to the nitroaldol (Henry) reaction or to the Michael reaction, respectively, with the formation of di- or polyfunctionalized nitroderivatives.15 The most commonly applied protocols to perform the above reactions require the use of basic catalysts under both homogeneous and heterogeneous conditions.5

Due to the great applicability of the Henry6 and the Michael5 reactions involving nitroalkanes, both these transformations were developed extensively, even under sonication7 or high pressure,8 and, although each of these methodologies has been widely studied, very often these suffer different drawbacks such as: (i, for the Henry reaction) low yields, retroaldol reaction, the formation of side products by the aldol condensation and Cannizzaro reaction of aldehyde or olefin formation; (ii, for the Michael reaction) low yields, the efficiency with a restricted class of electrophilic olefins, the need of ultrasound, and/or the demand of a large excess of nitro compound that, for valuable nitro derivatives, is a serious economic drawback. Consequently, the development of a new general, efficient catalyst for the title reactions is welcomed, especially a new heterogeneous one. Unfortunately, as clearly stated in recent reviews and reports, the classical synthetic routes are responsible for the production of large amounts of pollutant by-products.9 This drawback can be partly overcome by replacing stoichiometric processes with cleaner catalytic alternatives.10 Moreover, a further step toward environmentally friendly synthetic routes is represented by the application of solid catalysts 11 and by the development of solventless processes.12

In connection with our interest in the application of heterogeneous catalysis for fine chemicals preparation 13 with particular interest in the organicinorganic hybrid materials,14 we planned to find a new heterogeneous catalyst able to promote both (i) the Henry reaction and (ii) the Michael reaction of nitroalkanes to electron-poor alkenes under solventless conditions. To this end we tested different heterogeneous catalysts and, after several trials, we found that KG-60-NEt2 produced good results for both reactions. As shown in Table 1, alfa-nitroalcohols 3 (Scheme 1) are produced in good to excellent yields; it should be noted that the very mild reaction conditions prevent typical side reactions such as the retro-aldol reaction 5,6 or the dehydration of the 2-nitro alcohol into nitroalkene.15

The present method affords a diastereomeric mixture of nitroalkanols according to the most part of the reported procedures; this seems not to be a problem since the main uses are the conversion into alfa-nitro ketones 2,3,5,16 or conjugated nitroalkenes,5,17 in which at least one stereogenic centre is lost.

Synthetic results of conjugate addition of nitroalkanes to electron-poor olefins are reported in Table 2. A wide range of nitroalkanes and electron poor olefins underwent Michael addition by this procedure affording products 5 (Scheme 2) in good to excellent yield.

The different reactivity is obviously ascribable to the different activation of the electron-poor carbon-carbon double bond.18 Concerning the role played by the catalyst, as expected a possible diffusion effect into the pores of the catalyst is excluded due to the fact that the KG-60 silica is a macroporous material (pore distribution: 60-100 nm).

Finally, we faced the problem of catalyst recycling: at the end of the model reaction between 1-nitropropane and methyl vinyl ketone, the catalyst was filtered on a Buechner funnel, washed with dichloromethane, dried under vacuum and reused. The catalyst could be utilized with similar results for at least two further cycles (reaction: 80%; 1st recycle 78%; 2nd recycle: 79%).

In conclusion we have shown the utilization of KG-60-NEt2 as solid and reusable, solventless, catalyst in the formation of the carbon-carbon bond through nitroalkanes via the Henry and Michael reactions. It is noteworthy that the catalyst shows general applicability and good efficiency with all substrates utilized in both reactions.

Preparation of KG-60-NEt2:
The preparation of silica supported N,N-diethylpropylamine was performed following a modification of a procedure reported in the literature.19The KG-60 (5 g) was treated with N,N-diethyl-3-aminopropyltrimethoxysilane (45 mmol, 7.9 mL) in dry toluene (75 mL) at reflux for 24 h. After cooling, the mixture was filtered on a Buechner funnel and the solid washed with a Soxhlet apparatus for 16 h with a mixture of dichloromethane/diethyl ether 1/1. Characteristics of KG-60-NEt2 are the following: loading=0.99 mmol/g, surface area=309 m2/g, pore total volume=0.15 cm3/g, pore distribution 50-100 nm.

Typical procedure (Henry reaction) for the formation of 3g:


Nitroethane (157 mg, 2.1 mmol) was mixed with the hydrocinnamaldehyde (262 mg, 2.1 mmol), then, the catalyst KG-60-NEt2 (0.21 g) was added. After standing (stirring can be avoided since it does not change the efficiency of the reaction) at room temperature for the appropriate time (see Table 1) the mixture was extracted with EtOAc (5×20 mL), the catalyst was filtered off, the organic layer was evaporated and the crude product was purified by flash chromatography (cyclohexane/EtOAc, 7:3) giving 336 mg (80%) of the pure 3g.

Typical procedure (Michael reaction) for the formation of 5b:


1-Nitropropane [187 mg, 2.1 mmol, (4.2 mmol when the starting nitroalkane is nitroethane)] was mixed with methyl vinyl ketone (122 mg, 2.1 mmol), then, the catalyst KG-60-NEt2 (0.42 g) was added. After standing (stirring can be avoided since it does not change the efficiency of the reaction) at room temperature for the appropriate time (see Table 1) the mixture was extracted with EtOAc (5×20 mL), the catalyst was filtered off, the organic layer was evaporated and the crude product was purified by flash chromatography (cyclohexane/EtOAc, 8:2), affording 247 mg (80%) of the pure 5b.

Table 1.

 R R1 Time (h)(a) Yield(b)
a Me Me2CH 24 92
b MeCH2 Me2CH 19 78
c H Me2CH 16 77
d Me Me(CH2)2 24 75
e MeCH2 Me(CH2)2 22 94
f Me Me(CH2)3 15 95
g MeCH2 Me(CH2)3 14 75
h Me Ph(CH2)2 5 80

(a) Selected to avoid by-products formation.

(b) Yield of pure isolated product.

Table 2.

 R R1 EWG Time (h)(a) Yield(b) (%)

a Me H MeCO 3 75
b MeCH2 H MeCO 5 80
c Me Me MeCO 5 82
d Me(CH2)2 H MeCO 5 85
e Me(CH2)2 H EtCO 6 83
f Me H PhSO2 25 81
g Me Me PhSO2 25 90
h Me(CH2)2 H PhSO2 28 65
i MeCH2 H COOMe 26 61
j Me(CH2)2 H COOMe 30 62
k Me(CH2)2 H CN 15 58
l Me(CH2)4 H CN 16 56



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References
[1]Seebach, D.; Colvin, E. W.; Leher, F.; Weller, F.; Weller, T. Chimia (1979), 33, 118.
[2]Rosini, G.; Ballini, R. Synthesis (1988), 833-847.
[3] Rosini, G.; Ballini, R.; Petrini, M.; Marotta, E.; Righi, P. Org. Prep. Proc. Int. (1990), 22, 707-746.
[4] 4. Ballini, R.; Bosica, G. Recent Development in Organic Chemistry; Transworld Research Network: Trivandrum, (1997); Vol. 1, pp. 11-24.
[5] Ono, N. In The Nitro Group in Organic Synthesis; Feuer, H., Ed.; Wiley-VCH: New York, (2001).
[6] (a) Rosini, G. In Comprehensive Organic Synthesis; Trost, B. M., Ed.; Pergamon: New York, (1992); pp. 321340; (b) Luzzio, F. A. Tetrahedron (2001), 57, 915-945.
[7] Jouglet, B.; Bianco, L.; Rousseau, G. Synlett (1991), 907-908.
[8] (a) Sera, A.; Takagi, K.; Katayama, H.; Yamada, H. J. Org. Chem. (1988), 53, 1157-1161; (b) Misumi, Y.; Bulman, R. A.; Matsumoto, W. Heterocyclic (2002), 56, 599 606.
[9] Clark, J. H. Green Chem. (1999), 1, 18.
[10] Sheldon, R. Chem. Ind. (London ) (1997), 1215.
[11] Corma, A. Chem. Rev. (1995), 95, 559-614.
[12] Thomas, J. M.; Raja, R.; Sankar, G.; Johnson, B. F. G.; Lewis, D. W. Chem. Eur. J. (2001), 7, 2973-2978.
[13] a) Ballabeni, M.; Ballini, R.; Bigi, F.; Maggi, R.; Parrini, M.; Predieri, G.; Sartori, G. J. Org. Chem. (1999), 64, 1029-1032; (b) Ballini, R.; Bigi, F.; Gogni, E.; Maggi, R.; Sartori, G. J. Catal. (2000), 191, 348-353; (c) Ballini, R.; Bosica, G.; Maggi, R.; Ricciutelli, M.; Righi, P.; Sartori, G.; Sartorio, R. Green Chem. (2001), 3, 178-180; (d) Ballini, R.; Bosica, G.; Fiorini, D.; Maggi, R.; Righi, P.; Sartori, G.; Sartorio, R. Tetrahedron Lett. (2002), 43, 8445-8447.
[14] Demicheli, G.; Maggi, R.; Mazzacani, A.; Righi, P.; Sartori, G.; Bigi, F. Tetrahedron Lett. (2001), 42, 2401-2404.
[15] Rosini, G.; Ballini, R.; Petrini, M.; Sorrenti, P. Synthesis (1985), 515-517.
[16] a) Me`lot, J.-M.; Texier-Boullet, F.; Foucaud, A. Tetrahedron Lett. (1986), 27, 493; (b) Hurd, C. D.; Nilson, M. E. J. Org. Chem. (1955), 20, 927-936.
[17] (a) Barrett, A. G. M.; Graboski, G. G. Chem. Rev. (1986), 86, 751-762; (b) Kabalka, G. W.; Varma, R. S. Org. Prep. Proc. Int. (1987), 19, 283-328; (c) Ballini, R.; Castagnani, R.; Petrini, M. J. Org. Chem. (1992), 57, 2160-2162; (d) Ballini, R.; Palestini, C. Tetrahedron Lett. (1994), 35, 5731-5734; (e) Perekalin, V. V.; Lipina, E. S.; Berestovitskaya, V. M.; Efremov, D. A. Nitroalkenes; John Wiley & Sons: Chichester, (1994).
[18] Shenhav, H.; Rappoport, Z.; Patai, S. J. Chem. Soc. (B) (1970), 469-476.
[19] Cauvel, A.; Renard, G.; Brunel J. Org. Chem. (1997), 62, 749-751.

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I really would sooner avoid Al-Hg rdxn, mercury is evil.

Then again, plenty of people say so am I, but true or not, I would have to dispose of it somehow, and I do care about the environment, not the people that live in it, but just what is lived IN.

Does LAH rdxn give a lower yield than Al amalgam? At any rate, LAH will be the agent used to effect the reduction of the nitroalkene.

As for amine acetates...hmm.....is the acetate bit important, perhaps buffering the rxn? the canizzaro rxn is base-catalysed, and occurs in carbonyl compounds lacking an alpha proton, benzaldehydes in particular...so presumably, I would think, the stronger the base, the more likely canizzaro side products will be formed, I.E the benzylic alcohol and benzoic acid?

Think the acetate salt TETA would be a usable catalyst with good yields?

TY Lugh, will look at that later.

LAH is definately the method to be used in this case...its already on its way.

Cleaner workup and no fucking about making it environmentally safe.

I find that attitude abhorrent, and the actions you practise and advocate beyond vile and disgusting by orders of magnitude.


It is true that Big Industry pisses all over the regulations in place (or perhaps, that SHOULD be in place) and they often get away with it. In the case of heavy metals, some real nasty accidents have occurred, such as minamata disease, where Hg got dumped into the ocean, then people ate the local wildlife, or the rather nasty sounding itai-itai disease (japanese for 'ouch, ouch' due to the agonizing bone pains those afflicted had to put up with) when there was a similar release of Cd due to mining for IIRC, Au, victims ended up with a nasty mixture of osteomalacia, possibly pulmonary injury, and kidney failure).

Now I couldn't give a flying rat fuck about those people, nor nigh on any others. I would gleefully pull the trigger that wiped out perhaps 75% of the world's population and dance upon the mass heap of skulls piled up on the mass graves. As long as it didn't involve nuclear weapons, or biological weapons (save perhaps short-lived environmentally unstable weaponized viral agents, in cases where there is no chance of the virus causing continued environmental contamination or becoming endemic)

But I would have to think of the animals, and plant life that could be affected, hell, I wouldn't even use lead bullets to do the dirty work mopping up the survivors, most likely high-yield thermobaric munitions to wipe out villages and cities after the desirable populace had been evacuated, and steel bullets and bladed weapons to mop up the survivors.

Chucking Hg, Pb compounds, Cd, Be, or whatever into the local canal or pond is beyond the pale sedit, it really is not right.
Whilst its true I have given some stuff, like MeOH in small quantities, acetone, even, to my guilt, small quantities of CHCl2 and CCl3 (talking tens of ml not liters), I wouldn't just toss out heavy metal waste that I couldn't recover the metals from, but burn off the organics if possible and take the waste to the local dump, where they have facilities for disposing of it properly, rather than a lake, or landfill.

Those heavy metals don't just poison wildlife then bugger off, they STAY there, and bioaccumulate, the higher the predator, the more lower life that ingested the poison they eat, and the more it concentrates. Look at tuna, marlin, shark, swordfish etc. as used for food, they now advise pregnant women to avoid those larg, top-predator fish entirely during pregnancy due to the high levels of mercury (present as Hg(Me) or possibly Hg(2Me), two of the most vicious, insidious, virulent neurotoxins known to man (look up what happened to karen wetterhahn after exposure, through gloves, nearly instantly taken off of maybe a couple of hundred microliters of dimethylmercury)

Yes this shit gets dumped by those arsewipe big companies, it shouldn't, but it does. BUT, need you, me, or anyone else stoop to the same base level they do? If you don't give a toss about the environment, and you should do, consider this:

Clandestine or hobby chemist dumps a bucket full of contaminated filth in the local pond. There may or may not be more clandestine/hobby chemists around, but there may well be, each dumps their weekly bucket of filth into the pond, after their speed/MDMA cook etc, and sooner or later, nothing lives there anymore, or maybe they all still do, bar one rare, sensitive species, that you just contributed to knocking down several pegs on the CITES list. Or maybe, just maybe, you contaminated that one pond that was home to a species with an extremely localised distribution, and just slaughtered the very last of them.

Not only that, but it makes you, me, and home chemists everywhere look like junky scum, weather or not we are actually engaged in the production of drugs of any sort, recreational or otherwise. The authorities aren't picky, if they can make money by destroying somebodys life, they will do. Don't give them an excuse (short of cooking up what you want to cook up, money or otherwise, I don't care, that is the business of the individual), but when it comes to pouring nasty toxic waste into the environment-I have one thing, and one thing only to say.

DON'T FUCKING DO IT! IT IS WRONG!

I use to feel the same way, I really did until I really thought about it on another level without the knee jerk response society has trained me to have when dealing with "toxic" materials.

Like I said, I will state my full logic in a different thread sometime in the future but for now I don't want to lead a fine thread astray. I just see it like this, One gram of Hg is alot for a home chemist to be using. At the bottom of a lake it will have a very very slow dissolution rate. It will start in the bacteria and work its way up the food chain. By the time that entire little 1 gram blob is consumed the rest of the Hg will be spread from here to china is extremely trace amounts. Basicly figure the math on how much Hg would be contained in one square mile if one gram of Hg was equally spread over the entire world. Hg is not THAT toxic, its in your mouth more then likely right now, its more then likely in your water in doses greater then what that one gram would accumulate to. People use to drink it as immortality potions. Workers use to lay in vats of it.... ect...ect.. It is scary stuff but its highly over hyped. Dimethylmercury has given it its scare factor.


PS: Lugh, no arguing. discussing . I just feel that reducing it and sealing it up in an amalgum would release more of it into the enviroment then that single blob on the bottom of a pond.

I also wonder like pyramid if this is about reduction or condensation.
Regarding reductions -
LAH is NASTY! only those with balls of steel or shit for brains will work it in anything larger then microscale. Ive witnessed first hand the effects of a LAH mishap, and let me tell you, it aint a pretty sight. plus, considering all the positive progress made in nitrostyrene group reduction, it seems stupid and un-needed to LAH.
for nitroethenes (commonly called nitrostyrenes, condensation product of benzaldehydes and nitromethane) reduce well with Zn/HCl all the way to the primary amine. no need to reduce the double bond first. Works well both for 2,5-DMNS and 3,4,5-TMNS.
for nitrostyrenes, you must first reduce the double bond with borohydride as pyramid mentioned. failture to do will result in a mixture of oxime, ketone and maybe slight amounts of primary amine. Distillation of the resulting nitroalkane is recommended. pure nitroalkanes give better yields when reduced to the amine via Zn/HCl or Pd catalyzed CTH.
Pd Catalyzed CTH - Pd/C is used to reduce the nitro group much like Zn/HCl, post double bond reduction. Ammonium formate is an efficient hydrogen donor. lower alcohols are the solvent of choice. The reaction is very clean and workup is super easy. No reflux is needed.

regarding the condensation of benzaldehydes with nitroalkanes -
EDDA (ethylenediammonium diacetate, either prepared prior to reaction as a solid, or insitu) is indeed a good catalyst for the preparation of 2,5-DMNS. when done in isopropanol, the whole reaction mixture solidifies to a mass of orange crystals in an hour or less. I usually let it sit in the fridge overnight t omake sure all is out.
MeNH2.acetate is a very active koevengel catalyst. it is so active that too long reflux, or too much catalyst will induce dimerization and higher order polymerization. with benzaldehyde and nitroethane this is evident by a red color that develops. the use of a drying agent helps to reduce the temperature needed, the time needed and the yields by way of shifting the equilibrium to the right. this has a much more pronounced effect on nitropropenes then on nitrostyrenes.
Other amine acetates are adequate as well. Butylamine acetate works very well for the slow r.t. generation of nitroalkenes, usually taking a few weeks, but yields very well. just mix ingrediants and let it sit in the dark for a while. other amines such as cyclohexylamine acetate also work well.
the use of azeotropic drying techniques (with toluene or benzene as solvent) are also appropriate to drive the water away.
IIRC there are also those who advocate the use of short microwave bursts to effect reaction progress. Lugh is the one to ask about this i think.

I can only comment on a couple of things.
I know condensation of 4-methyl-2,5-dimethoxybenzaldehyde works well with EDDA, with both nitromethane and nitroethane.
While it is nice to perform reductions with LAH (quite fun, invigorating process) if the experimenter intends on further reactions I would greatly recommend to forget LAH for reductions.
The experimenter obviously has sources, so he should get some NaBH4!
But hey, do a couple of reductions with the LAH and see how the yield goes. I guarantee the yield will be the same or better with NaBH4 and there is no need for dry solvents and inert atmospheres.
Also the NaBH4 Zn reduction works great for 4-Me-2,5-DMBA.

And the benzaldhydes are cheap if you don't buy them from suppliers, which isn't that smart anyway they are watched.
Go from 2-methylhydroquinone which is dirt cheap and methylate it, trimethyl phosphate or DMS work(don't know how MeI would go). Formylate with Sulfuric Duff which works for this substrate (or use POCl3/DMF), there is the benzaldehyde.
It is a cheap route, all the chemicals used in the processes have uses in other things too and a resourceful person can get them easily.

Of course though I can understand if you can't be bothered doing this but it's all suggestions, what I mention above works for sure, it is cheap and besides the methylating agent everything is quite obtainable.

Yes ethylenediammonium diacetate, good stuff. Try MeNH2.acetate too though some time! I'd like to hear about that.
 

Good luck

Edit as you edited while i posted:
High purity products (benzaldehydes, nitroalkanes, everything) can be made at home easily. Just because it's self made does not mean it can't be pure. I'm not saying that's what you implied, but when watched reagents can be made easily in good purity I would say you should do it rather than buy them..even when you have a good source. Best advice that was ever given to me : Don't Risk Buying Watched Reagents!
Now, doesn't mean you can't get some ether and whatnot, even NaBH4 is so common it only falls somewhat under that advice...but EtNo2 and substituted aldehydes, that's what I take the advice for.

Limpet did you get that paper I posted for you over in the short question thread? It covers the various catalyst and bases used in deep detail. Everything you need to know about this reaction is contained in that paper.

rhodium has a nice html with yields of various benzaldehydes with nitroalkanes and EDDA as amine salt catalyst. it can be found at h--p://erowid.org/archive/rhodium/chemistry/edda.html
Here are my notes which i have on hand on general condensations. i cant seem to find the notes on 3,4,5-TMB.
2,5-Dimethoxybenzaldehyde : (ipa as rxn solvent)
EDDA(10mol%) + nitromethane, r.t. -> 95%-quantitative yield, recrystallized once from ipa.
EDDA(10mol%) + nitroethane, r.t.-reflux -> 50-60% yield, recrystallized from ipa.
EDDA(10mol%) + nitroethane + 4a mol sieves(40g/mol), 1hour reflux-> 80-90%, recrystallized once from ipa.
methylamine acetate (10mol%) + nitroethane, 45-60minutes reflux -> ~75% yield, recrystallized from ipa.
Benzaldehyde : (methanol or ipa as rxn solvents)
EDDA(10mol%) + nitroethane, r.t.-reflux ->50-60% yield, recrystallized from methanol. low yields makes post reaction crystallization hard and requires either a seed crystal or heavy wall scratching.
methylamine.acetate(10mol%) + nitroethane, 45minutes reflux (heating turned off before any red color is apparent) -> 75-85% yield, recrystallized from methanol.
methylamine.acetate(5-7mol%) + nitroethane, 60minutes reflux (heating turned off before any red color is apparent) -> 75-85% yield, recrystallized from methanol.
Piperonal : (methanol or ipa as rxn solvents)
methylamine.acetate (10mol%) + nitroethane, 45-60minutes reflux -> ~85% yield.
NaOH/HCl 2 step reaction + nitroethane -> ~80% yield.
Slow n-butylamine + nitroethane (as rxn solvent), r.t. for 3 weeks -> ~80-85% yield.

gotta run now, will complete the list another time...

yea some stuff is bunk, other is good. non the less, rhodiums is a good archive for lots of stuff. the ethylenediamine bit works as described in rhodium.