A General Aminocatalytic Method for the Synthesis of Aldimines
摘要:
A general and efficient biomimetic method for the synthesis of aldimines from aldehydes and compounds bearing the NH2 group in the presence of pyrrolidine as a catalyst has been developed. These organocatalytic reactions, based on the application of the concept of nucleophilic catalysis, proceed with outstanding yields in the absence of acids and metals under simple conditions and minimum experimental manipulation. The method has been mainly applied to the synthesis of N-sulfinyl and N-sulfonyl imines, but its general validity has been proven with the preparation of representative N-phosphinoyl, N-alkyl, and N-aryl imines. These unprecedented reactions, which presumably occur via iminium activation without requiring acidic conditions, are an interesting and competitive alternative to the classical methods for preparing aldimines.
Synthesis of Chiral C2-Symmetric 1,2-Diamines by the Addition of Organolithium Reagents to N,N′-Bis[(S)-1-phenylethyl]ethanediimine
作者:Gianluca Martelli、Stefano Morri、Diego Savoia
DOI:10.1016/s0040-4020(00)00782-1
日期:2000.10
The additions of alkyl-, phenyl- and vinyllithium reagents to N,N′-bis[(S)-1-phenylethyl]ethanediimine in THF at −78°C and in DME at −60°C gave high yields of 1,2-diamines with low stereocontrol. Care was taken to quench the reaction mixtures with de-aerated H2O to avoid formation of N-alkylidene-1-phenylethylamines which were formed through homolysis of the dilithium 1,2-diamides to give α-amido radicals
在-78°C的THF中和在-60°C的DME中,向N,N'-双[(S)-1-苯基乙基]乙二亚胺中添加烷基,苯基和乙烯基锂试剂可得到1,2的高收率-低立体控制的二胺。小心地用脱气的H 2 O淬灭反应混合物,以避免形成N-亚烷基-1-苯基乙胺,后者是通过1,2-二酰胺二锂的均质化反应生成的α-酰胺基与O 2反应而形成的。/ H 2 O在淬灭步骤中。戊二烯基-,肉桂基-和1-三甲基甲硅烷基烯丙基锂试剂仅以高收率和中等至良好的非对映选择性提供线性1,2-二胺。