Carboxylate as a promising and valuable directing group has attracted a great deal of attention.However,employing it as a traceless direction group has rarely been reported.We developed the ruthenium-catalyzed amidation of substituted benzoic acids with isocyanates via directed C–H functionalization followed by decarboxylation to afford the corresponding metasubstituted N-aryl benzamides,in which the carboxylate serves as a unique,removable directing group.Notably,this protocol can provide an efficient alternative to access meta-substituted N-aryl benzamides,which are much more difficult to prepare than ortho-substituted analogues.
Xian-Ying ShiXue-Fen DongJuan FanKe-Yan LiuJun-Fa WeiChao-Jun Li
An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide（NBS） in the presence of K3PO4 was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields（up to 95%） in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of a-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition- cyclization pathway was proposed.
CHEN Zhan-guo XIA Wei WEN Hua WANG Dan LI Ya-nan HU Jun-li
