Oxidative conversion of N,N-dimethylhydrazones derived from aliphatic and heteroaromatic aldehydes into nitriles with hydrogen peroxide or 3-chloroperoxybenzoic acid
A Novel, One-Pot Synthesis of α-<i>C</i>-Cyanohydrazines in the Presence of Lithium Perchlorate/Diethylether Solution (5.0 M)
作者:Akbar Heydari、Robabe Baharfar、Mohsen Rezaie、Saied M. Aslanzadeh
DOI:10.1246/cl.2002.368
日期:2002.3
Condensation of N,N-dimethylhydrazine, an aldehyde in lithium perchlorate/diethylether solution (5.0 M) gave N,N-dimethylhydrazone, which were treated with trimethylsilyl-cyanide to afford α-C-cyanohydrazine. These compounds are important precursors of nitrogen-substituted reagents.
A reaction of N,N-disubstituted hydrazones (1) with bases has been investigated. N - Methyl - N -tosylhydrazones of aliphatic carbonyl compounds have been shown to combine with primary and some secondary aliphatic amines to form α-aminodialkyldiazenes (2) hitherto unknown, and with triethylamine and alcoholic solutions of alkalies to form symmetric azines (10). Some structural factors contributing
Deconjugation of α,β-unsaturated esters and an intramolecular Michael reaction of bis-α,β-unsaturated esters with trialkylsilyl trifluoromethanesulfonate in the presence of tertiary amine: synthesis of (±)-ricciocarpin A
1, 6 and 8 with trialkylsilyltrifluoromethanesulfonate in the presence of a tertiaryamine gave, via silyl dienol ethers, the corresponding deconjugated esters 3, 7 and 9 as the major products, respectively. Reaction of bis-α,β-unsaturated esters 12a and 12b with a trialkylsilyl trifluoromethansulfonate in the presence of a tertiaryamine caused an intramolecularMichaelreaction to produce the cyclopentanes
的α,β -不饱和酯的治疗1,6和8中,在叔胺的存在下用三烷基甲硅烷三氟甲烷磺酸酯,得到,通过甲硅烷基烯醇醚,相应的去缀合酯3,7和9分别为主要产品。双-α,β-不饱和酯12a和12b与三烷基甲硅烷基三氟甲磺酸酯在叔胺存在下的反应引起分子内迈克尔反应,从而产生环戊烷14a和20a以及环己烷14b和20b。同时获得了由迈克尔-迪克曼串联或分子内狄尔斯-阿尔德反应形成的双环化合物21a和21b。将环己烷衍生物14b转化为倍半萜烯((±)-ricciocarpin A 22)的外消旋体。
Intramolecular Michael reaction using trialkylsilyl trifluoromethanesulfonates and tertiary amine system: total synthesis of (±)-ricciocarpin A
IntramolecularMichaelreaction of bis-α,β-unsaturated esters 1 forming 2 was carried out by the action of a trialkylsilyltrifluoromethanesulfonate in the presence of a tertiaryamine; the product was transformed into ricciocarpin A 8.
Additions regioselectives d'imines et d'hydrazones metallees aux α-enones
作者:L. Gorrichon-Guigon、S. Hammerer
DOI:10.1016/0040-4020(80)88005-7
日期:1980.1
β-unsaturated ketones was studied, using different reaction times and temperatures. Dissociation of the functional group (imine or hydrazone) in the adducts and regioselectivity in their condensation reactions are discussed. The first example of reversible addition to the carbonyl group of an enone is demonstrated for the reaction between trans chalcone and