Enantioselective Bromocycloetherification by Lewis Base/Chiral Brønsted Acid Cooperative Catalysis
作者:Scott E. Denmark、Matthew T. Burk
DOI:10.1021/ol203033k
日期:2012.1.6
A binary catalyst system for the enantioselective bromocycloetherification of 5-arylpentenols is described. The combination of an achiral Lewis base and a chiralBrønstedacid affords good enantioselectivities for the cyclization of Z configured 5-arylpentenols to form bromomethyltetrahydrofurans. The constitutional site selectivity is highly dependent upon the aromatic substituent and the configuration
Chlorohydrins and oxaheterocycles are synthetically valuable building blocks for diverse natural products and therapeutic substances. A highly efficient Ir/f-phamidol-catalyzed asymmetric hydrogenation of ω-chloroketones was successfully developed, and various chlorohydrins and oxaheterocycles were obtained divergently with excellent yields and enantioselectivities (up to >99% yield and >99% ee). Synthetic