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 efficient synthesis of 4-halo-2,5-dihydro-1,2-oxaphosphole 2-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 Suzuki cross-coupling of the resulting vinylic chlorides with dicyclohexyl(2,4,6-trimethoxyphenyl)phosphane
通过 CuX2 介导的二乙基 1,2-allenylphosphonates 的直接卤环化,开发了一种方便有效的 4-halo-2,5-dihydro-1,2-oxaphosphole 2-oxides 合成方法。产量从中等到极好。还研究了轴向到中心手性转移的效率。建立了所得氯乙烯与二环己基(2,4,6-三甲氧基苯基)膦(LB-Phos)作为配体的进一步 Suzuki 交叉偶联。