DABCO-Catalyzed 1,4-Bromolactonization of Conjugated Enynes: Highly Stereoselective Formation of a Stereogenic Center and an Axially Chiral Allene

作者：Zhang Wen; Xu Huadong; Xu Hui; Tang Weiping^*

来源：Journal of the American Chemical Society, 2009, 131(11): 3832-+.

DOI：10.1021/ja8099008

A DABCO-catalyzed highly regio- and stereoselective syn-1,4-bromotactonization of conjugated enynes was discovered. The 1,4-addition occurred selectively over 1,2-addition for most enynes. In contrast to anti 1,2-addition to alkenes, where two adjacent stereogenic centers are created, 1,4-addition across conjugated enynes can produce a stereogenic center and an axially chiral allene simultaneously. Enynes with Z and E configurations yielded products with complementary stereochemistries at the newly generated stereogenic center and axially chiral. allene. Di-, tri-, or even tetrasubstituted allenes together with lactones can be efficiently and selectively prepared from this enyne bromolactonization reaction.

• 出版日期2009-3-25