Spontaneous formation of PMB esters using 4-methoxybenzyl-2,2,2-trichloroacetimidate
作者:Jigisha P. Shah、Christopher M. Russo、Kyle T. Howard、John D. Chisholm
DOI:10.1016/j.tetlet.2014.01.097
日期:2014.3
Carboxylic acids are converted to the corresponding 4-methoxybenzyl (PMB) esters with 4-methoxybenzyl-2,2,2-trichloroacetimidate in the absence of an acid catalyst. This operationally simple procedure is a highly effective method for the formation of PMB esters. The reaction is promoted by the carboxylic acids themselves in excellent yields (72–99%). Sterically hindered carboxylic acids, which provide
Ester Formation via Symbiotic Activation Utilizing Trichloroacetimidate Electrophiles
作者:Nivedita S. Mahajani、Rowan I. L. Meador、Tomas J. Smith、Sarah E. Canarelli、Arijit A. Adhikari、Jigisha P. Shah、Christopher M. Russo、Daniel R. Wallach、Kyle T. Howard、Alexandra M. Millimaci、John D. Chisholm
DOI:10.1021/acs.joc.9b00745
日期:2019.6.21
Trichloroacetimidates are useful reagents for the synthesis of esters under mild conditions that do not require an exogenous promoter. These conditions avoid the undesired decomposition of substrates with sensitive functional groups that are often observed with the use of strong Lewis or Brønsted acids. With heating, these reactions have been extended to benzyl esters without electron-donating groups. These inexpensive
A Convenient Preparation of<i>p</i>-Methoxybenzyl Esters
作者:Meng F. Wang、Bernard T. Golding、Gerard A. Potter
DOI:10.1080/00397910008087040
日期:2000.12
Abstract Carboxylic acids are conveniently and efficiently protected as their p-methoxybenzyl esters under very mild conditions using the pre-formed reagent N,N-diisopropyl-O-(4-methoxybenzyl)isourea, and this method allows selective protection of carboxylic acids in the presence of other functionalities such as enolisable ketones and alcohol groups.