Introduction of a substituent into ortho-position of β-aryl group in a vinyl bromide resulted in the preferential formation of a vinyl cation in the photolysis. It is considered that the steric repulsion of β-aryl groups makes a convenient conformation for an electron transfer from the aromatic ring to the halogen atom in the radical pair.
将取代基引入
乙烯基溴中 β-芳基的邻位导致在光解中优先形成
乙烯基阳离子。据认为,β-芳基的空间排斥为电子从芳环转移到自由基对中的卤素原子提供了便利的构象。