Kinetic Resolution of Tertiary Alcohols: Highly Enantioselective Access to 3-Hydroxy-3-Substituted Oxindoles
作者:Shenci Lu、Si Bei Poh、Woon-Yew Siau、Yu Zhao
DOI:10.1002/anie.201209043
日期:2013.2.4
Enantioselective: The first highlyenantioselectivekineticresolution of 3‐hydroxy‐3‐substituted oxindoles has been developed through oxidative esterification catalyzed by a N‐heterocyclic carbene (see picture). This method uses a simple procedure and provides 3‐hydroxy‐oxindoles with various substituents at the 3‐position in excellent enantiopurity. S=selectivity.
Synthesis of 2-substituted 3-chlorobenzofurans <i>via</i> TMSCl-mediated nucleophilic annulation of isatin-derived propargylic alcohols
作者:Zhou Sun、Kuirong Xiang、Hua Tao、Liqun Guo、Ying Li
DOI:10.1039/c8ob01731j
日期:——
A TMSCl-mediated cascade annulation of isatin-derived propargylicalcohols for the synthesis of 2-substituted 3-chlorobenzofurans is now reported. Mechanistic investigations showed that this proceeded through a sequential Meyer–Schuster rearrangement/nucleophilic addition/intramolecular annulation. TMSCl not only acts as a promoter, but also acts as a chlorine source in this protocol.