A Positional Scanning Approach to the Discovery of Dipeptide-Based Catalysts for the Enantioselective Addition of Vinylzinc Reagents to Aldehydes
作者:Christopher M. Sprout、Meaghan L. Richmond、Christopher T. Seto
DOI:10.1021/jo051342w
日期:2005.9.1
crude form as catalysts for the asymmetric addition of vinylzinc reagents to aldehydes to give chiral allylic alcohols. Three sites of diversity on the ligands were optimized using a positional scanning approach. The optimized structure from the library, ligand 54, was found to catalyze the formation of 10 different (E)-allylic alcohols with enantioselectivities ranging from 90% to 95% ee. This ligand was
通过平行固相法合成了基于二肽N-酰基乙二胺的配体的组合库。这些配体以粗制形式进行筛选,以作为乙烯基锌试剂不对称加成到醛中的催化剂,得到手性烯丙基醇。使用位置扫描方法优化了配体上的三个多样性位点。发现来自库的最佳结构,配体54,催化形成10种不同的(E)-烯丙基醇,其对映选择性为90%至95%ee。该配体对于芳族和α-支化醛以及衍生自大体积和直链末端炔烃的乙烯基锌试剂均有效。