Direct Enantioselective Amination of α-Ketoesters Catalyzed by an Axially Chiral Guanidine Base
作者:Masahiro Terada、Kei Amagai、Kenichi Ando、Eunsang Kwon、Hitoshi Ube
DOI:10.1002/chem.201101076
日期:2011.8.8
β‐functional! Direct enantioselective amination of α‐ketoesters with azodicarboxylates was demonstrated using an axially chiral guanidine base catalyst, which enabled efficient access to enantioenriched multifunctionalized ketoesters with an aliphatic substituent at the β‐position. Subsequent nucleophilic addition to the β‐hydrazinyl‐α‐ketoester at the reactive ketone yields the corresponding β‐hydrazinyl‐α‐hydroxy
β功能!使用轴向手性胍碱催化剂证明了α-酮酸酯与偶氮二羧酸酯的直接对映选择性胺化,该催化剂能够有效地获得在β-位置带有脂族取代基的对映体富集的多官能化酮酸酯。后续亲核加成到β肼基α酮酯在反应性酮得到在高对应的β肼基α羟基酯顺diastereo-和对映选择性(参见方案)。