128732-38-7Relevant articles and documents
Palladium/Xiao-Phos-Catalyzed Kinetic Resolution of sec-Phosphine Oxides by P-Benzylation
Dai, Qiang,Liu, Lu,Zhang, Junliang
supporting information, p. 27247 - 27252 (2021/11/17)
P-stereogenic tert- and sec-phosphines have wide applications in asymmetric catalysis, materials, and pharmaceutical chemistry, however, their practical synthesis still constitutes a significant challenge. Herein, a successful kinetic resolution of rac-se
Photochemistry of phosphate esters: An efficient method for the generation of electrophiles
Givens, Richard S.,Matuszewski, Bogdan,Athey, Phillip S.,Robert Stoner
, p. 6016 - 6021 (2007/10/02)
The photochemical cleavage of benzyl diethyl phosphates, 1a-g, has been examined in tert-butyl alcohol, which produces the corresponding benzyl tert-butyl ether as the major solvolysis product upon direct irradiation. The multiplicity of the reactive excited state has been established as the singlet state. Evidence favoring an intermediate benzyl cation-phosphate ion pair formed from photofragmentation includes oxygen-18 scrambling, racemization of chiral benzyl phosphates, and substituent effects on the rate of reaction. The existence of an electrophilic intermediate is further supported by a linear free energy relationship for the rate of disappearance of 1, kdis, with Hammett σ, which gave a ρ value of -0.90 and for the rate of appearance of 2, kapp, a Hammett ρ value of -0.97. Possible mechanisms including an electron transfer either before or after homolysis or simple heterolysis of the ester bond are evaluated.
