Preparation of Osmium η<sup>3</sup>-Allenylcarbene Complexes and Their Uses for the Syntheses of Osmabenzyne Complexes
作者:Ting Bin Wen、Ka-Ho Lee、Jiangxi Chen、Wai Yiu Hung、Wei Bai、Huacheng Li、Herman H. Y. Sung、Ian D. Williams、Zhenyang Lin、Guochen Jia
DOI:10.1021/acs.organomet.6b00102
日期:2016.5.23
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.