Department of Social Design Engineering, National Institute of Technology, Kochi College, 200-1 Monobe, Otsu, Nankoku, Kochi, 783-8508, Japan.
Department of Materials Science and Engineering, National Institute of Technology, Kochi College, 200-1 Monobe otsu, Nankoku, Kochi, 783-8508, Japan.
Chem Asian J. 2020 Jun 17;15(12):1858-1862. doi: 10.1002/asia.202000386. Epub 2020 May 27.
A facile and convenient synthesis of the chiral phthalide framework catalyzed by cationic iridium was developed. The method utilized cationic iridium/bisphosphine-catalyzed asymmetric intramolecular carbonyl hydroacylation of 2-keto benzaldehydes to furnish the corresponding optically active phthalide products in good to excellent enantioselectivities (up to 98% ee). The mechanistic studies using a deuterium-labelled substrate suggested that the reaction involved an intramolecular carbonyl insertion mechanism to iridium hydride intermediate. In addition, we investigated the kinetic isotope effect (KIE) of intramolecular hydroacylation with deuterated substrate and determined that the C-H activation step is not included in the turnover-limiting step.
一种由阳离子铱催化的手性邻苯二甲酸酐骨架的简便合成方法被开发出来。该方法利用阳离子铱/双膦催化的 2-酮苯甲醛不对称分子内羰基氢酰化反应，以良好至优异的对映选择性（高达 98%ee）得到相应的光学活性邻苯二甲酸酐产物。使用氘标记的底物进行的机理研究表明，反应涉及铱氢化物中间体的分子内羰基插入机理。此外，我们还研究了氘代底物的分子内氢酰化的动力学同位素效应（KIE），并确定 C-H 活化步骤不包括在周转限制步骤中。
