Palladium-Catalyzed Asymmetric Synthesis of 2-Alkynyl Oxacycles
作者:David S. B. Daniels、Amber L. Thompson、Edward A. Anderson
DOI:10.1002/anie.201105720
日期:2011.11.25
cyclizations of cyclic and acyclic propargylic carbonates give 2‐alkynyl oxacycles. The reactions proceed with very high stereoselectivity for both syn‐ and anti‐disubstituted furans and pyrans, and with exceptional regioselectivity. In addition, two‐directional cyclizations of bis‐propargylic carbonate substrates yield bifurans with complete stereocontrol for all diastereomers.