The CN shuffle: The described intramolecular alkenyl‐ and acylcyanation reaction of activated alkenes proceed by cleavage of a CN bond. This protocol provides access to functionalized acyclic nitriles with quaternary carbon centers under neutral and mild reaction conditions, demonstrates broad scope, and good functional‐group compatibility and versatility. Y=O or CHR4; R1,R4=electron‐withdrawing group;
Treatment of 2-acyl (or sulfonyl)-1-cyano-1, 2-dihydroisoquinolines with bromine and CH3OH gave 2-acyl (or sulfonyl)-4-bromo-1-cyano-3-methoxy-1, 2, 3, 4-tetrahydroisoquinolines in a highly stereoselective manner in high yields. The stereochemistry, with 1, 4-cis and 3, 4-trans configurations, was determined by X-ray crystallography.
Enantioselective Alkylation of Reissert Compounds in Phase Transfer Catalysed Reactions
作者:Maria D. Rozwadowska、Danuta Brózda、Krzysztof Hoffman
DOI:10.3987/com-05-s(t)35
日期:——
IsoquinolineReissertcompounds were alkylated under phase-transfer reaction conditions using chiral quaternary ammonium salts derived from Cinchona alkaloids as catalysts. The best stereoselectivity (ee up to 65%) was achieved in the alkylation of 1-cyano-2-phenoxycarbonyl-1.2-dihydroisoquinoline (1d), catalysed by N-benzylcynchoninium bromide (3a), carried in toluene/50% NaOH biphasic system.