Department of Chemistry and Biochemistry, California State University, Los Angeles, California 90032, USA.
Org Lett. 2010 Jul 2;12(13):3100-3. doi: 10.1021/ol101122u.
Arylphosphines and dialkylbiarylphosphines react with singlet oxygen to form phosphine oxides and phosphinate esters. For mixed arylphosphines, the most electron-rich aryl group migrates to form the phosphinate, while for dialkylbiarylphosphines migration of the alkyl group occurs. Dialkylbiarylphosphines also yield arene epoxides, especially in electron-rich systems. Phosphinate ester formation is increased at high temperature, while protic solvents increase the yield of epoxide. The product distribution provides evidence for Buchwald's recent conformational model for the aerobic oxidation of dialkylbiarylphosphines.
芳基膦和二烷基联芳基膦与单线态氧反应生成氧化膦和膦酸酯。对于混合芳基膦，最富电子的芳基基团迁移形成膦酸酯，而对于二烷基联芳基膦，烷基基团发生迁移。二烷基联芳基膦也会生成芳烃环氧化物，特别是在富电子体系中。膦酸酯的形成在高温下增加，而质子溶剂会增加环氧化物的产率。产物分布为 Buchwald 最近提出的有氧氧化二烷基联芳基膦的构象模型提供了证据。
