Catalytic Performance of Tantalum-eta~2Alkyne Complexes[TaCl_3(R~1C=CR~2)L_2]for Alkyne Cyclotrimerization

摘要

Structurally characterized tantalum-eta~2-alkyne complexes[TaCl_3(eta~2-EtC(ident to)CEt)L_2](1,L2-1,2-dimethoxyethane(DME);2,L = py)acted as catalysts for the Cyclotrimerization of terminal alkynes.The catalytic reaction proceeded at 25 C within few hours and the trisubstituted benzenes were obtained without the formation of linear oligomers.A new tantalum compleXhaving a terminal alkyne ligand,[TaCl_3(eta~2-Me_3SiC(ident to)CH)(dme)](3),was prepared,and its catalytic performance was also investigated.