文献类型：期刊文献

英文题名：Synthesis and structures of gold and copper carbene intermediates in catalytic amination of alkynes

作者：Wang, Jiwei[1,2];Cao, Xiaoming[3,4];Lv, Shichang[1,2];Zhang, Caiyun[1,2];Xu, Sheng[1,2];Shi, Min[1,2,5];Zhang, Jun[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, 130 Mei Long Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem, 130 Mei Long Rd, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Sch Chem & Mol Engn, Ctr Computat Chem, 130 Mei Long Rd, Shanghai 200237, Peoples R China;[4]East China Univ Sci & Technol, Sch Chem & Mol Engn, Res Inst Ind Catalysis, 130 Mei Long Rd, Shanghai 200237, Peoples R China;[5]Chinese Acad Sci, Shanghai Inst Organ Chem, State Key Lab Organometall Chem, 354 Fenglin Rd, Shanghai 200032, Peoples R China

年份：2017

卷号：8

外文期刊名：NATURE COMMUNICATIONS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000395503200001)】；

基金：Financial support from Shanghai Pujiang Talent Program (11PJ1402500) and the National Natural Science Foundation of China (21671066, 21171056, 21333003, 21303051, u1162111, and u1362111) is greatly acknowledged.

语种：英文

摘要：Metal carbenes are often proposed as reactive intermediates in the late transition metal-catalysed transformations of alkynes. Owing to their high reactivity, however, isolation and structural characterization of metal carbene intermediates in these transformations has remained unknown. Herein, we report the isolation of two acyclic gold and copper carbene intermediates in either Au(I)- or Cu(I)- catalysed cyclization of N-alkynyl formamidines through five-exo-dig cyclization. X-ray diffraction, C-13 NMR spectra data and computational analyses provide evidence for the formation of a gold carbene intermediate with a carbocation-like electronic character. Using the intrinsic bond orbital (IBO) approach, we also evaluate the p-stabilizing effects of organic substituents at the carbene carbon atom in the gold carbene intermediate. Another rare six-membered copper carbene complex is also obtained through 6-endo-dig cyclization. These metal carbenes have proven reactive toward oxidation. The metal-promoted cyclization of N-alkynyl formamidine provides a facile approach to synthesize metal carbene species.