Manganese catalyzed ß‐methylation of alcohols by methanol

Titelangaben

Schlagbauer, Martin ; Kallmeier, Fabian ; Irrgang, Torsten ; Kempe, Rhett:
Manganese catalyzed ß‐methylation of alcohols by methanol.
In: Angewandte Chemie International Edition. Bd. 59 (2020) Heft 4 . - S. 1485-1490.
ISSN 1521-3773
DOI: https://doi.org/10.1002/anie.201912055

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Abstract

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. In addition, 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.