Steric and kinetic effects of changing solvent and reagent in grignard reactions on some 4-substituted cyclohexanones
作者:Claudia Cianetti、Giorgio Di Maio、Vito Pignatelli、Pietro Tagliatesta、Elisabetta Vecchi、Errico Zeuli
DOI:10.1016/s0040-4020(01)91842-3
日期:1983.1
stereochemistry and relative rates of Grignard reactions on some 4R-substituted cyclohexanones (R=tBu, Me, OMe. CO2Me, OCOPh and Cl) have been determined under two separate reaction conditions (MeMgI in C6H6 and MeMgCl in THF). The results of our studies indicate that substrates containing an ester group have a higher reaction order in Grignard rcactant than other groups when reactions were carried out in the aromatic
在两个单独的反应条件下(C 6 H 6中的MeMgI和在THF中的MeMgCl )确定了一些4R取代的环己酮(R = tBu,Me ,OMe。CO 2 Me,OCOPh和Cl)上格氏反应的立体化学和相对速率)。我们的研究结果表明,当在芳族溶剂中进行反应时,含酯基的底物在格氏试剂中的反应顺序要高于其他基团。对于在THF中进行的反应而言并非如此。假设含有极性基团(至少OMe和Cl)的化合物通过在轴向构象中具有该基团的过渡态发生反应,则可以更好地理解立体化学产物比率和相对反应速率。