Borthakur Ishani, Maji Milan, Joshi Abhisek, Kundu Sabuj
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, Uttar Pradesh (U.P.), India.
J Org Chem. 2022 Jan 7;87(1):628-643. doi: 10.1021/acs.joc.1c02625. Epub 2021 Dec 13.
Herein, we demonstrated an efficient protocol for reductive alkylation of azides/nitro compounds via a borrowing hydrogen (BH) method. By following this protocol, selective mono- and dialkylated amines were obtained under mild and solvent-free conditions. A series of control experiments and deuterium-labeling experiments were performed to understand this catalytic process. Mechanistic studies suggested that the Ir(III)-H was the active intermediate in this reaction. KIE study revealed that the breaking of the C-H bond of alcohol might be the rate-limiting step. Notably, this solvent-free strategy disclosed a high TON of around 5600. Based on kinetic studies and control experiments, a metal-ligand cooperative mechanism was proposed.
在此，我们展示了一种通过借氢（BH）方法对叠氮化物/硝基化合物进行还原烷基化的有效方案。按照该方案，在温和且无溶剂的条件下获得了选择性单烷基化和二烷基化胺。进行了一系列对照实验和氘标记实验以了解该催化过程。机理研究表明，Ir(III)-H是该反应中的活性中间体。动力学同位素效应（KIE）研究表明，醇的C-H键断裂可能是限速步骤。值得注意的是，这种无溶剂策略显示出高达约5600的高总转化数（TON）。基于动力学研究和对照实验，提出了一种金属-配体协同机制。
