Substituent-dependent reactivity in aldehyde transformations: 4-(phenylethynyl)benzaldehydes versus simple benzaldehydes
作者:Isamu Katsuyama、Pandurang V. Chouthaiwale、Hai-Lei Cui、Yuji Ito、Ayumi Sando、Hiroaki Tokiwa、Fujie Tanaka
DOI:10.1016/j.tet.2013.03.056
日期:2013.5
Effects of substituents on transformations of 4-(phenylethynyl)benzaldehydes and related benzaldehydes were analyzed in aldol and thiazolidine formation reactions. The aldol reaction of 4-cyanobenzaldehyde was 54-fold faster than that of 4-methoxybenzaldehyde. In contrast, the aldol reaction of 4-(4-cyanophenylethynyl)benzaldehyde was only 1.4-fold faster than that of 4-(4-methoxyphenylethynyl)benzaldehyde
在醛醇和噻唑烷形成反应中分析了取代基对4-(苯基乙炔基)苯甲醛和相关苯甲醛的转化的影响。4-氰基苯甲醛的羟醛反应比4-甲氧基苯甲醛的羟醛反应快54倍。相反,4-(4-氰基苯基乙炔基)苯甲醛的醛醇缩合反应仅比4-(4-甲氧基苯基乙炔基)苯甲醛的醛醇缩合反应快1.4倍。取代基的电子特征在二苯基乙炔系统中的影响远比在简单苯系统中的低。