α,α-Disubstituted Boron Enolates in the Asymmetric Synthesis of Quaternary Carbon Centers
作者:E. Diane Burke、James L. Gleason
DOI:10.1021/ol0364428
日期:2004.2.1
[reaction: see text] Reduction of alpha,alpha-disubstituted thioglycolate amides with lithium di-tert-butylbiphenylide affords alpha,alpha-disubstituted enolates with high Z/E selectivity. Transmetalation of the enolates with dicyclohexylboron bromide facilitates highly diastereoselective aldol reaction with aromatic and alpha,beta-unsaturated aldehydes.
[反应:见正文]用二叔丁基联苯锂还原α,α-二取代的硫代乙醇酸酯酰胺可提供高Z / E选择性的α,α-二取代的烯醇化物。用二环己基溴化硼对烯醇化物的金属重金属化促进了与芳族和α,β-不饱和醛的高度非对映选择性的羟醛反应。