Asymmetric Addition of Phenylacetylene to Aldehydes Catalyzed by β-Sulfonamide Alcohol-Titanium Complex
作者:Zhaoqing Xu、Li Lin、Jiangke Xu、Wenjin Yan、Rui Wang
DOI:10.1002/adsc.200505453
日期:2006.3
A series of β-sulfonamide alcohol ligands were synthesized from L-phenylalanine. Titanium complexes of these compounds were used to catalyze the asymmetric addition of phenylacetylene to a number of aldehydes. When the conditions were optimized, 20 mol % of ligand 8a catalyzed the reaction with high enantioselectivity (up to 98% ee) and good yield (up to 92%). When a small amount of MeOH was added
由L-苯丙氨酸合成了一系列的β-磺酰胺醇配体。这些化合物的钛络合物用于催化苯乙炔向许多醛的不对称加成。当条件最优化时,20 mol%的配体8a以高对映选择性(最高98%ee)和良好的收率(最高92%)催化反应。当将少量的MeOH作为改性剂添加到反应中时,仅需5 mol%的配体即可在非常温和的条件下有效催化反应,从而产生高达99%的ee和良好的收率。