Total Synthesis of (+)-Isatisine A: Application of a Silicon-Directed Mukaiyama-Type [3 + 2]-Annulation
作者:Jihoon Lee、James S. Panek
DOI:10.1021/acs.joc.5b00051
日期:2015.3.20
synthesis highlights the use of a highly diastereoselective Mukaiyama-type [3 + 2]-annulation of allylsilane 5 with the unsaturated aldehyde 9a to assemble the functionalized tetrahydrofuran core of isatisine A. A convergentroute to the framework of the natural product was established that employed a substrate-controlled indole coupling that was followed by a late-stage intramolecular copper(I)-mediated
Totalsynthesis of (+)-isatisine A is described based on the application of a silyl-directed Mukaiyama-type [3 + 2]-annulation for the preparation of a fully substituted furan core. The indole branch forming the quaternary carbon center at C2 was constructed by addition to an intermediate N-acyliminium ion derived from aminal 4. In addition, the fused tetracyclic framework including furan core was