ELECTRONIC EFFECT OF SUBSTITUENTS AND MECHANISM ON THE FORMATION OF DIETHYL 3-OXO-3-ARYLPROPYL PHOSPHONATES
作者:Jen-Wen Yu、Chien-Keun Chong、Steve K. Huang
DOI:10.1080/10426509708043563
日期:1997.7.1
The reaction of aryl P-chloroethyl ketones with triethyl phosphite to give gamma-ketophosphonates was studied kinetically. This reaction follows a second order overall and involves a carbonyl group-assisted (CGA) initializing step, followed by a stereoselective pathway to gamma-ketophosphonates. A linear Hammett plot reveals that the rho value is 1.51 (r=0.994), and the transition state is accelerated by the para- halogen on the phenyl group. The results confirm the two-stage mechanism and rule out an S-N(2) mechanism being responsible for the formation of diethyl 3-oxo-3-arylpropyl phosphonates 3.
SYNTHESIS OF DIETHYL 3-ARYL-3-OXOPROPYLPHOSPHONATES