Nucleophilic substitution reactions of (η6-fluorotoluene)Cr(CO)3 and (η6-fluoroanisole)Cr(CO)3 toward phenylacetylide, fluorenyl, indolinyl and carbazolinyl lithium: crystal structures of tricarbonyl[η6-(1,2-diphenylethynyl)benzene]chromium and tricarbonyl[η6-(1,4-fluorenyl)toluene]chromium
作者:Fung-E Hong、Shih-Chun Lo、Ming-Woei Liou、Lung-Fang Chou、Chu-Chieh Lin
DOI:10.1016/0022-328x(96)06131-1
日期:1996.6
(4c) with lithium phenylacetylide (3). The formation of ortho- and meta-products, 7b, 8a and 7a, produced in the above reaction demonstrates that the reaction was by no means through a straightforward nucleophilic substitution mechanism. These results provided support for the mechanism proposed by Pauson and Brookhart, in which the nucleophile attacked the carbon atom of the phenyl ring not bearing
三羰基[ η 6 - (1,2- diphenylethynyl)苯]铬(8A)与三羰基[沿着得到η 6 - (2-苯基乙炔基)茴香醚]铬(7B)和三羰基[ η 6 - (3-苯基乙炔基)茴香醚]铬(7A从三羰基()的反应η 6 -fluoroanisol)铬(4C)与苯基乙炔锂(3)。原产物和元产物7b,8a和7a的形成在上述反应中产生的α,表明该反应决不是通过直接的亲核取代机理进行的。这些结果为Pauson和Brookhart提出的机理提供了支持,其中亲核试剂攻击不带有离去基团的苯环的碳原子,随后氢迁移并最终消除离去基团以获得芳香性。推测是由7b与过量3的反应获得了8a。用质谱,红外,1 H,13 C NMR谱表征化合物。8a的分子结构已通过X射线衍射研究确定。晶体数据如下:斜方晶系,P BCA,。