Mechanochemical Approach for Air-Tolerant and Extremely Fast Lithium-Based Birch Reductions in Minutes.
Angew Chem Int Ed Engl
; 62(21): e202217723, 2023 May 15.
Article
em En
| MEDLINE
| ID: mdl-36944574
ABSTRACT
Birch reduction has been widely used in organic synthesis for over half a century as a powerful method to dearomatize arenes into 1,4-cyclohexadiene derivatives. However, the conventional Birch reduction reaction using liquid ammonia requires laborious procedures to ensure inert conditions and low temperatures. Although several ammonia-free modifications have been reported, the development of an operationally simple, efficient, and scalable protocol remains a challenge. Herein, we report an ammonia-free lithium-based Birch reduction in air without special operating conditions using a ball-milling technique. This method is characterized by its operational simplicity and an extremely short reaction time (within 1â
min), probably owing to the in situ mechanical activation of lithium metal, broad substrate scope, and no requirement for dry bulk solvents. The potential of our flash Birch reaction is also demonstrated by the efficient reduction of bioactive target molecules and gram-scale synthesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article