Methyl propiolate coupling at the Fe(CO)2(PEt3)2 fragment
摘要:
The in situ solution mixture of Fe(CO)(2)(PEt3)(2)(N-2) 3a and (mu-N-2)[Fe(CO)(2)(PEt3)(2)](2) 3b reacts with HC=CCOOMe to afford an acetylene Fe(CO)(2)(PEt3)(2)(eta(2)-HC=CCOOMe) 4a and an acetylido hydride complex Fe(CO)(2)(PEt3)(2)(H)(C=CCOOMe) 4b as primary products. Compounds 4a and 4b are in equilibrium. The equilibrium mixture is irreversibly converted to a vinylidene species Fe(CO)(2)(PEt3)(2)(C=CHCOOMe) 5 in the presence of silylated silica. Addition of further equivalents of HC=CCOOMe to 5 leads to the isolation of carbonyl[2,4,6-tris(methyoxycarbonyl)-hexa-1,3,5-trien-1,5-diyl]bis(triethylphosphane)iron 9 and dicarbonyl[methoxycarbonyl(1,4-di-methoxycarbonyl-buta-1,3-dien-2-y)vinylidene]bis(triethylphosphane)iron 10 as iron-bound trimerization products of HC=CCOOMe. 10 was characterized by a single crystal X-ray diffraction study. (C) 1997 Elsevier Science S.A.
Methyl propiolate coupling at the Fe(CO)2(PEt3)2 fragment
摘要:
The in situ solution mixture of Fe(CO)(2)(PEt3)(2)(N-2) 3a and (mu-N-2)[Fe(CO)(2)(PEt3)(2)](2) 3b reacts with HC=CCOOMe to afford an acetylene Fe(CO)(2)(PEt3)(2)(eta(2)-HC=CCOOMe) 4a and an acetylido hydride complex Fe(CO)(2)(PEt3)(2)(H)(C=CCOOMe) 4b as primary products. Compounds 4a and 4b are in equilibrium. The equilibrium mixture is irreversibly converted to a vinylidene species Fe(CO)(2)(PEt3)(2)(C=CHCOOMe) 5 in the presence of silylated silica. Addition of further equivalents of HC=CCOOMe to 5 leads to the isolation of carbonyl[2,4,6-tris(methyoxycarbonyl)-hexa-1,3,5-trien-1,5-diyl]bis(triethylphosphane)iron 9 and dicarbonyl[methoxycarbonyl(1,4-di-methoxycarbonyl-buta-1,3-dien-2-y)vinylidene]bis(triethylphosphane)iron 10 as iron-bound trimerization products of HC=CCOOMe. 10 was characterized by a single crystal X-ray diffraction study. (C) 1997 Elsevier Science S.A.