Synthesis,Structures,and Catalytic Properties of Ruthenium Complexes Bearing Diphosphinidenecyclobutene Ligands (DPCB-Y)

摘要

Dinuclear ruthenium complexes bearing l,2-diaryl-3,4-bis(2,4,6-tri-t-butylphenyl-phosphinidene)cyclobutene ligands (DPCB-Y),[RuCl(mu-Cl)(CO)(DPCB-Y)]_2 (Y = H (4a),OMe (4b),CF_3 (4c)),have been prepared in 80-30% yields by the treatment of Ru(eta~3-C_3H_5)Cl(CO)_3 with DPCB-Y in toluene,followed by with dry-HCl in CH_2C1_2.Complexes 4a-c combine with Et_2O or H_2O in CD_2C1_2 to afford mononuclear species RuCl_2(CO)(Et_2O)(DPCB-Y) or RuCl_2(CO)-(H_2O)(DPCB-Y),respectively.Complex 4b serves as a highly efficient catalyst for hydrosilylation of terminal alkynes (RC ident to CH) with HSiMe_2Ph.Thus,the catalytic reactions using 1 or 0.5 mol% of 4b proceed readily at room temperature to give (Z)-RCH=CHSiMe_2Ph in over 98% selectivity.Similarly,p-diethynylbenzene is converted to (Z,Z)-bis{2-(dimethylphenylsilyl)ethenyl}benzene in almost perfect selectivity.