Novel Pyranylidene Complexes from Group 6 Transition Metals and β-Ethynyl α,β-Unsaturated Carbonyl Compounds
作者:Kouichi Ohe、Koji Miki、Tomomi Yokoi、Fumiaki Nishino、Sakae Uemura
DOI:10.1021/om0006763
日期:2000.12.1
1-carbamoyl-2-ethynylcycloalkenes and metals is a key route to these Fischer-type oxacarbene complexes. The crystal structure of the 6-methoxy-2H-pyranylidene−tungsten complex 2b has been determined by X-ray diffraction. New pyranylidene complexes undergo [4 + 2] cycloaddition reactions with acetylenes to give aromatic rings together with the liberation of metal hexacarbonyls.
共轭烯炔羰基化合物(例如1-(烷氧基羰基)-2-乙炔基环烯烃和1-氨基甲酰基-2-乙炔基环烯烃)与Mo(CO)5 ·NEt 3和W(CO)5 ·THF的反应得到相应的6-烷氧基-和6-氨基-2 H-吡喃基-钼和-钨配合物。由1-(烷氧基羰基)-或1-氨基甲酰基-2-乙炔基环烯烃和金属生成的共轭亚乙烯基-烯-羰基配合物的环异构化反应是通往这些费歇尔型氧杂卡宾配合物的关键途径。6-甲氧基-2 H-吡喃基-钨配合物2b的晶体结构通过X射线衍射确定。新的亚吡咯烷配合物与乙炔进行[4 + 2]环加成反应,以生成芳环以及金属六羰基的释放。