W-nitrostyrene

If the nitro group is located at the ethylenic fragment, one-electron transfer initiates dimerization of the developing anion radicals. a-Nitrostilbene, w-methyl-w-nitrostyrene, and a-nitro-(3-ferrocenylethylene give anion radicals that dimerize spontaneously. It is interesting to compare reactions of cyclo-octatetraene dipotassium (C8H8K2) with a-nitro... 

A further example of the use of copolymers of acrylonitrile and Cinchona alkaloids in asymmetric synthesis has been reported 127 thus these polymers catalyse the addition of benzyl mercaptan to w-nitrostyrene to give consistently an excess of the (+)-enantiomer of the adduct. 

It is interesting that when the functional groups are not directly attached to the aromatic ring, orientation cannot be predicted from a consideration of the point of highest electron density. Cinnamic acid (XII),7 w-nitrostyrene (XIII),8 and 2-phenylethenesulfonyl chloride (XIV),9 all orient predominantly ortho-para, although we should expect these positions to be electronically deficient. 

In w-nitrostyrene, for example, we should expect the resonance forms XV to XVIII to contribute importantly to the structure of the molecule, and we should therefore expect substitution to occur in the mcta position. The reason for the ortho-para orientation of these compounds is not clear ... 

Clearly, PhOCCl selects among the first 3 substrates as an electrophile (preferring the electron-rich p-methoxystyrene), but it selects among the last 4 substrates as a nucleophile (preferring the electron-poor />-trifluoromethyl- and w-nitrostyrenes.) Figure 4, which depicts a plot of log ( i) vs. a" " or a constants, makes the point dramatically. 

Slotta and Heller (109, 110) prepared their starting material, viz., trimethoxyphenylpropionic acid by condensation of the substituted benzaldehyde with malonic acid and reduction of the resulting cinnamic acid. Mescaline was then obtained by Hofmann degradation of the trimethoxyphenlypropionamide. Kindler and Peschke (103) synthesized very pure, crystallized mescaline by condensation of 3 4 5-trimethoxy-benzaldehyde with potassium cyanide, acetylation, and catalytic reduction to the amine. Slotta and Szyska (111, 112) improved Spath s first synthesis, obtaining mescaline directly by the electrolytic reduction of w-nitrotrimethoxystyrene. Hahn and Wassmuth (113, 114) started from elemicine and first prepared trimethoxyphenylacetaldehyde by ozonization. The oxime was then reduced to mescaline. Kindler (115) and Kindler and Peschke (38, 103) improved the catalytic reduction of w-nitrostyrenes to the corresponding phenethylamines. Hahn and Rumpf (116) described the preparation of mescaline by reduction of w-nitrotrimethoxystyrene with Adam s catalyst. A review has been published by Jensch (117). 

The substrate used for assay purposes was diethyl maleate. Among the most active substrates were w-nitrostyrene and 3,4-dimethoxy- J-sty ene, ethylvinyl ketone, hexene-l-ai, and cycIohex-2-ene-l-one. The enzjTne is closely associated with the other glutathione transferases in rat liver preparations. When a rat liver supernatant was dialyzed, 50% of the activities of glutathione S-alkyitransferase and iS poxidetransferase were lost but over 80% of the jS-alkenetransferase was retained. The enzyme has not been obtained free of substantial amounts of the jS-aryltransferase. 

Several papers report on the nucleophilic reactivity of dithiocarbamate ions towards alkyl halides, 1,2-dibromoalkyl compounds, alkyl and aryl chloroformates, chloroacetic acid, chloroacetates, 3-halo-genophthalides, sulphenyl chlorides, sultones, and trialkylam-monium compounds. Examples of a similar reactivity of dithiocarbazate anions have also appeared. " A series of papers deal with addition or addition-elimination reactions of dithiocarbamate - or dithiocarbazate anions with w-nitrostyrene, 2-thioxo-, 2-oxo-, and 2-imino-5-methoxycarbonylmethylidene-4-thiazolidones, dimethyl acetylenedicar-boxylate, and NN -dialkyl phenylpropiolamidines. S-Monoalkylated N-cyanodithioimidocarbonates (492) underwent oxidative ring-closure to give 3-halogeno-l,2,4-thiadiazole sulphides (493) on treatment with halogenating agents. ... 

Teichmann, H., Thierfelder, W., and Weigt, A., P-functionalization of P-nitrostyrenes with trialkyl phosphites, /. Prakt. Chem., 319, 207, 1977. 

N 18.67% wh ndls (from hexane), mp 87-88° was prepd by adding nitroform to a soln of (3-nitrostyrene in MeOH, addg w heating at 40° for 4 hrs, and cooling filtering the product. 

The intrinsic rate constants for thiolate ion addition to 76-Cr and 76-W are substantially larger than those for alkoxide ion addition. This is similar to the previously mentioned higher intrinsic reactivity of thiolate ions compared to amine nucleophiles for the addition to a-nitrostilbene and p-nitrostyrene. It can be understood in terms of the soft-soft interaction of the thiolate ion with the carbene complex which is more advanced than C S bond formation at the transition state.184... 

W/cbae/-adducts obtained by Enders and Seki (ret. 39) from ketones and frans-p-nitrostyrene, using 20 mol-% of L-proline as catalyst in methanol at ambient temperature... 

Trimethylsilyloxy-p-nitrostyrene was the target of Knoevenagel condensation uf 2-Lrimethyl-siloxybenzaldehyde with nitromethane in the presence of w-butylamine as base. 13C NMR spectra 20 were obtained from the product of the reaction. What has happened ... 

Wang W, Wang J, Li H (2005) Direct, highly enantioselective pyrrolidine sulfonamide catalyzed Michael addition of aldehydes to nitrostyrenes. Angew Chem Int Ed Engl 44 1369-1371... 

This procedure has been used in the preparation of other nitrostyrenes in the following yields o-nitrostyrene (40%), />-nitrostyrene (41%),2 and 3-nitro-4-hydroxystyrene (60%).2 A better procedure for more volatile styrenes involves simultaneous decarboxylation and codistillation with quinoline from the reaction flask. This method has been used to prepare the following styrenes o-chlorostyrene (50%),4 w-chlorostyrene (65%),4 -chlorostyrene (51%),4 m-bromostyrene (47%),4 o-methoxystyrene (40%),4 />-methoxystyrene (76%),4 w-cyano-styrene (51%),3 and -formylstyrene (52%).9... 

Thiolacetic acid, then a little tri-n-butylamine added to a suspension of 3,4-niethylenedioxy-j -nitrostyrene in benzene, and allowed to stand overnight l-(3,4-methylenedioxyphenyl)-l-acetylthio-2-nitroethane. Y 75%. F. e. s. K. V. Bhat and W. G. McCarthy, J. Pharm. Sci. 53, 1545 (1964). 

A soln. of (E)-4-methoxy-/ -methyl- -nitrostyrene in acetone as solvent irradiated ca. 5 hrs. under Ng with the Pyrex-filtered light of a 100 w. high-pressure Hg-lamp -> product. Y 89%. F. e., also in benzene, s. I. Saito, M. Takami, and T. Matsuura, Tetrah. Let. 1975, 3155. 

P-nitrostyrene. (b) L. W. A. van Berkom, G. J. T. Kuster, R. de Gelder, H. W. Seheeren, Eur. J. Org. Chem. 2004,4397-4404. Synthesis and rearrangement of Ai-oiganyloxy P-lactams derived liom a (4+2)/(3 + 2) sequential cycloaddition reaction involving enol ethers and nitro alkenes. 

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