Photooxidation of mixed aryl and biarylphosphines.
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.
Zhang
Dong
D
Department of Chemistry and Biochemistry, California State University, Los Angeles, California 90032, USA.
Celaje
Jeff A
JA
Agua
Alon
A
Doan
Chad
C
Stewart
Timothy
T
Bau
Robert
R
Selke
Matthias
M
D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010087:Oxides / Q000138:chemical synthesis* / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*; D010777:Photochemistry; D013237:Stereoisomerism
D004952:Esters; D010087:Oxides; D010720:Phosphines; D010100:Oxygen