Ketene-forming eliminations from aryl bis(4′-chlorophenyl)acetates promoted by R<sub>2</sub>NH–R<sub>2</sub>NH<sub>2</sub><sup>+</sup>in aqueous MeCN. Change of mechanism
作者:Sang Yong Pyun、Dong Choon Lee、Ju Chang Kim、Bong Rae Cho
DOI:10.1039/b303231k
日期:——
Eliminationreactions of (4'-ClC6H4)2CHCO2C6H3-2-X-4-NO2 promoted by R2NH-R2NH2+ in 70 mol% MeCN (aq.) have been studied kinetically. The reactions are second-order and exhibit Brönsted beta = 0.44-0.86 and /beta(lg)/ = 0.41-0.71. The Brönsted beta decreased with a poorer leavinggroup and /beta(lg)/ increased with a weaker base. The results are consistent with an E2mechanism. When X=H, the reaction