Reaction of SilyLketenes with Carbanions: Simple Preparation of .ALPHA.-SilyLketones Using Organocerium Reagents.
作者:Shuji AKAI、Shinji KITAGAKI、Satoshi MATSUDA、Yasunori TSUZUKI、Tadaatsu NAKA、Yasuyuki KITA
DOI:10.1248/cpb.45.1135
日期:——
Preparation of α-silylketones 1 by the reaction of three kinds of silylketenes 3a-c with various organometallic reagents 4 was studied. Although the use of n-BuLi, MeMgBr, Me2CuLi, Et3Al, and Et2Zn resulted in complicated reactions, organocerium reagents 4 (M=CeCl2) added selectively to the carbonyl carbon of 3 to generate enolate anions A, which were treated with aqueous NH4Cl or alkyl halides 5 to give 1. Seventeen α-silylketones 1a-q were prepared in 31-99% yields from three components, 3, alkyl- or arylcerium reagents 4, and proton or alkyl halides 5. This method was applied to a regiocontrolled preparation of two isomeric α-silylketones 1r, s.
通过三种硅基酮烯3a-c与各种有机金属试剂4的反应,研究了α-硅基酮1的制备。虽然使用n-BuLi、MeMgBr、Me2CuLi、Et3Al和Et2Zn会导致复杂的反应,但有机铈试剂4(M=CeCl2)选择性地加入到3的羰基碳上,生成烯醇负离子A,随后用氯化铵水溶液或烷基卤化物5处理得到1。通过三种组成部分3、烷基或芳基铈试剂4和质子或烷基卤化物5,共制备了17种α-硅基酮1a-q,产率为31-99%。该方法还被应用于两个异构体α-硅基酮1r、s的区域选择性合成。