Solvent, chelation and concentration effects on the benzannulation reaction of chromium carbene complexes and acetylenes
作者:Kin Shing Chan、Glen A. Peterson、Timothy A. Brandvold、Katherine L. Faron、Cynthia A. Challener、Carol Hyldahl、William D. Wulff
DOI:10.1016/0022-328x(87)80037-2
日期:1987.11
in solvent or substituents on the acetylene. The reactions of aryl complexes with acetylenes are quite sensitive to the nature of the solvent and the acetylene. The highest selectivities and efficiencies for the benzannulated product from the reactions of aryl complexes are with solvents of low coordinating ability. Solvents with intermediate coordinating ability and small size give high selectivity
一些铬卡宾络合物的(CO)的反应中5 CrC(OME)R(R = PH,Õ -OMePh,p -OMePh,ö -O-tBuPh,1-C 6 ħ 9,1-C 5 ħ 7 O)与各种乙炔(R'CCR检查2,R 1,R 2 = H,ME等,正镨,pH值,森达3)在低至高配位能力的溶剂中使用。简单的α,β-不饱和配合物的反应对苯环化产物的高选择性不受乙炔上溶剂或取代基变化的影响。芳基配合物与乙炔的反应对溶剂和乙炔的性质非常敏感。芳基配合物反应生成的苯甲环化产物的最高选择性和效率是配位能力低的溶剂。具有中等配位能力和小尺寸的溶剂对于与二取代的乙炔反应形成环丁烯酮具有很高的选择性。具有高配位能力的溶剂会产生最少的选择性反应,并产生大量的茚产物。一个o卡宾配合物的芳基取代基上的-甲氧基可在苯环化反应过程中螯合至金属中心,并且在乙腈中,改变产物分布,有利于环丁烯酮产物。(CO)取代的复合物的氨基,5 CrC(NME