Gold-Catalyzed Access to 1<i>H</i>-Isochromenes: Reaction Development and Mechanistic Insight
作者:Eder Tomás-Mendivil、Clément F. Heinrich、Jean-Claude Ortuno、Jérôme Starck、Véronique Michelet
DOI:10.1021/acscatal.6b02636
日期:2017.1.6
take part in the reaction mechanism. Employing Hantzsch ester (HEH) as nucleophile, it has been impossible to isolate the corresponding gold–alkenyl specie; however, when methanol was used as solvent (and nucleophile), the expected chelate gold–vinyl complex was isolated and unambiguously characterized by X-ray analysis. When HEH is present in the alcoholic reaction mixture, isotopic studies show that
邻位金催化的多米诺环化/亲核反应已经研究了-羰基炔基芳基。因此,已选择2-(吡啶-2-基乙炔基)苯甲醛来分离可能参与反应机理的关键中间体。利用汉茨sch酯(HEH)作为亲核试剂,不可能分离出相应的金-烯基物种。然而,当甲醇用作溶剂(和亲核试剂)时,预期的螯合金-乙烯基络合物被分离出来,并通过X射线分析明确鉴定。当乙醇反应混合物中存在HEH时,同位素研究表明,金-乙烯基络合物的Au-C键的裂解是通过原金属化途径进行的,而不是通过合理的金属-氢化物还原消除机理进行的。最后,为了扩大先前报道的环化/还原反应的范围,