Synthetic and Computational Studies on Rh<sup>III</sup>-Catalyzed Redox-Neutral Cascade of Carbenoid Functionalization and Dephosphonylative Annulation
作者:Suvankar Bera、Partha Mondal、Debabrata Sarkar、Vijay Babu Pathi、Sourav Pakrashy、Ayan Datta、Biswadip Banerji
DOI:10.1021/acs.joc.1c00311
日期:2021.5.21
A Rh(III)-catalyzed regioselective redox-neutral cascade process of carbenoid functionalization followed by dephosphonylative annulation of benzoic acids with α-diazo-β-keto phosphonate has been realized, which led to the direct synthesis of a privileged 3-substituted isocoumarin scaffold. To the best of our knowledge, this is the first report of a complete redox neutral method to synthesize isocoumarins
已经实现了Rh(III)催化的类胡萝卜素官能团的区域选择性氧化还原中性级联过程,然后用α-重氮-β-酮膦酸酯对苯甲酸进行去膦酰基化环化反应,从而直接合成了优先的3-取代的异香豆素骨架。 。据我们所知,这是使用CHH功能化策略合成异香豆素的完整氧化还原中性方法的首次报道。在此反应的催化循环中,苯甲酸的原位碳原子与重氮碳原子之间存在C–C偶联的两种可能途径:(i)协同1,2-芳基转移和(ii)逐步金属–卡宾形成,然后迁移插入。DFT研究预测,与逐步途径相比,协同途径的活化能更低,为1.5 kcal / mol。