Efficient Synthesis of 4-Halo-2,5-dihydro-1,2-oxaphosphole 2-Oxides from 1,2-Allenylphosphonates and CuX2 and Subsequent Suzuki Cross-Coupling of the C-Cl Bonds
作者:Ning Xin、Shengming Ma
DOI:10.1002/ejoc.201200228
日期:2012.7
A convenient and efficientsynthesis of 4-halo-2,5-dihydro-1,2-oxaphosphole2-oxides through CuX2-mediated direct halocyclization of diethyl 1,2-allenylphosphonates was developed. The yields range from moderate to excellent. The efficiency of axial-to-central chirality transfer has also been studied. Further Suzukicross-coupling of the resulting vinylic chlorides with dicyclohexyl(2,4,6-trimethoxyphenyl)phosphane
CuX<sub>2</sub>-Mediated Halolactonization Reaction of Monoesters of 1,2-Allenyl Phosphonic Acids and Their Suzuki Cross-Coupling Reaction
作者:Fei Yu、Xiongdong Lian、Jinbo Zhao、Yihua Yu、Shengming Ma
DOI:10.1021/jo802051r
日期:2009.2.6
(X = Cl, Br) halolactonization of monoesters of 1,2-allenyl phosphonicacids is presented. The reaction proceeded smoothly under the mild condition for differently substituted allenic substrates giving the 4-halo-2,5-dihydro[1,2]oxaphosphole 2-oxides in good yields. The Suzuki cross-coupling reaction of these bromides and even chlorides with organic boronic acids under the catalysis of PdCl2(Sphos)2