Brønsted Acid-Promoted Cyclizations of 1-Siloxy-1,5-diynes
作者:Jianwei Sun、Sergey A. Kozmin
DOI:10.1021/ja055054t
日期:2005.10.1
We have developed the first HNTf2-promoted 5-endo-dig cyclizations of 1-siloxy-1,5-diynes, which proceed with concomitant formation of C-Hal bonds as a result of halide abstraction from a halocarbon by the intermediate alkenyl cation. This process is enabled by a chemoselective activation of the more electron-rich siloxy alkyne moiety of the diyne cyclization precursor and represents an efficient and highly diastereoselective method for assembly of a range of beta-halo enones.