Inorganic Chemistry II-Catalyst Design, University of Bayreuth, 95440, Bayreuth, Germany.
Angew Chem Int Ed Engl. 2020 Jan 20;59(4):1485-1490. doi: 10.1002/anie.201912055. Epub 2019 Dec 12.
We report an earth-abundant-metal-catalyzed double and single methylation of alcohols. A manganese catalyst, which operates at low catalyst loadings and short reaction times, mediates these reactions efficiently. A broad scope of primary and secondary alcohols, including purely aliphatic examples, and 1,2-aminoalcohols can be methylated. Furthermore, alcohol methylation for the synthesis of pharmaceuticals has been demonstrated. The catalyst system tolerates many functional groups among them hydrogenation-sensitive examples and upscaling is easily achieved. Mechanistic investigations are indicative of a borrowing hydrogen or hydrogen autotransfer mechanism involving a bimetallic K-Mn catalyst. The catalyst accepts hydrogen as a proton and a hydride from alcohols efficiently and reacts with a chalcone via hydride transfer.
我们报告了一种丰富的地球金属催化的醇的双重和单一甲基化。锰催化剂在低催化剂负载和短反应时间下操作，有效地介导这些反应。广泛的伯醇和仲醇，包括纯脂肪族的例子，和 1,2-氨基醇可以被甲基化。此外，已经证明了用于合成药物的醇甲基化。该催化剂体系可以容忍许多官能团，包括氢化敏感的例子，并且易于放大。机理研究表明，涉及双金属 K-Mn 催化剂的氢转移或氢自转移机制。该催化剂有效地接受醇的质子和氢化物，并通过氢化物转移与查尔酮反应。
