Selective Cleavage of Aryl Methyl Ether Moiety of Aryloxy Aryl Methyl Ether by 48% Hbr/Tetra-n-butylphosphonium Bromide
作者:Kijun Hwang、Seungki Park
DOI:10.1080/00397919308012606
日期:1993.11
Abstract Aryl methyl ether moiety in the molecule containing arylarylether part along with aryl methyl ether part is selectively cleaved to give the desired substituted phenol in excellent yield by using 48% HBr in the presence of tetra-n-butylphosphonium bromide
The kinetics of the reaction of 2-chloro-3-nitropyridine (ortho-like) and 2-chloro-5-nitropyridine (para-like) with a series of aryloxide ions were studied in methanol at different temperatures. Plots of Delta H-not equal versus Delta S-not equal for both reactions gave good straight lines with isokinetic temperatures of 168 and 195 degrees C. Good linear relationships were obtained from the plots of log k(2) against sigma degrees values with relatively large negative rho values indicating the formation of Meisenheimer sigma-complex intermediates. Plots of log k(2) against pK(a) values gave good straight lines indicating that the reactions show an appreciable degree of bond formation in the transition state. An addition-elimination mechanism is suggested. Copyright (C) 1999 John Wiley & Sons, Ltd.
Hwang, Ki-Jun; Park, Seung Ki, Synthetic Communications, 1990, vol. 20, # 7, p. 949 - 954
作者:Hwang, Ki-Jun、Park, Seung Ki
DOI:——
日期:——
SAMMES P. G.; SERRA-ERRANTE G.; TINKER A. C., J. CHEM. SOC. PERKIN TRANS., PART 1, 1979, NO 7, 1736-1739
作者:SAMMES P. G.、 SERRA-ERRANTE G.、 TINKER A. C.
DOI:——
日期:——
HWANG, KI-JUN;PARK, SEUNG KI, SYNTH. COMMUN., 20,(1990) N, C. 949-954