The bifunctional quinine-derived thiourea catalyst 14 was found to catalyze the direct amination of unprotected 3-aryl and aliphatic substituted oxindoles with di-tert-butyl azodicarboxylate (DBAD) to construct a tetrasubstituted stereogenic carbon center at the C-3 position of oxindoles in good to excellent yield and enantioselectivity.
发现双功能
奎宁衍生的
硫脲催化剂14催化了未保护的3-芳基和脂族取代的羟
吲哚与偶氮二叔丁基二
羧酸酯(
DBAD)的直接胺化反应,从而在羟
吲哚的C-3位置构建了一个四取代的立体碳中心。优良至优异的产率和对映选择性。