Pd(II)-catalyzed coupling cyclization of 2,3-allenoic acids with allylic halides. An efficient methodology for the synthesis of beta-allylic butenolides.
An effective method for the synthesis of beta-allyl polysubstituted butenolides from the easily available allylic halides and 2,3-allenoic acids is described. By using this method optically active butenolides can be obtained. According to the results presented in this paper, the reaction may proceed via three consecutive steps: cyclic oxypalladation of the allene, insertion of the C=C bond in allylic halides, and beta-dehalopalladation.
Ma
Shengming
S
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, P R China. masm@mail.ac.cn
Yu
Zhanqian
Z