Treatment of OsCl2(PPh3)(3) with HC=CAr (Ar = Ph, p-tolyl) produced the eta(3)-allenylcarbene complexes OsCl2(=CAr-eta(2)-CH=C=CHAr)(PPh3)(2). Reactions of the eta 3-allenylcarbene complexes with gold alkynyls Au(C=CR)(PPh3) (R = Ph, p-tolyl, TMS, Bu-n, CH(OEt)(2)) or copper(I) alkynyls Cu(C=CR) (R = Ph, TMS) in the presence of HNEt3Cl produced the osmabenzynes Os{=CC(R)=C(CH2Ar)CH=CAr}Cl-2(PPh3)(2). Computational studies suggest that the osmabenzynes are formed through electrocyclization of osmium alkynyl-allenylcarbene intermediates followed by protonation with HNEt3Cl.
Syntheses of Metallabenzynes from an Allenylcarbene Complex
作者:Ting Bin Wen、Wai Yiu Hung、Herman H. Y. Sung、Ian D. Williams、Guochen Jia
DOI:10.1021/ja0429061
日期:2005.3.9
Treatment of the allenylcarbene complex OsCl2(=CPh-CH=C=CHPh)(PPh3)2 with (PPh3)AuCCR in the presence of HNEt3Cl in CH2Cl2 produces osmabenzynes Os(CC(R)=C(CH2Ph)CH=CPh)Cl2(PPh3)2.