Synlett 2023; 34(18): 2215-2219
DOI: 10.1055/s-0040-1720074
cluster
Modern Boron Chemistry: 60 Years of the Matteson Reaction

Hemiboronic Acid-Catalyzed Reduction of α,β-Unsaturated Ketones with Reagent-Controlled Chemoselectivity

Jason P. G. Rygus
,
Daniel B. Boateng
,
Dennis G. Hall
We thank the Natural Sciences and Engineering Research Council of Canada (grant RGPIN-2017-05086 for D.G.H.; CGS-D scholarship for J.P.G.R.) and the Province of Alberta for financial support.


Dedicated to Professor Donald Matteson in recognition of his ­seminal contributions to organoboron chemistry.

Abstract

The use of an air-stable cationic hemiboronic acid catalyst for the chemoselective reduction of enones is described. By changing the identity and stoichiometry of the silane reducing agent, either the conjugate reduction products or the fully reduced products can be obtained in high selectivity. In contrast to analogous reactions catalyzed by air- and moisture-sensitive borane catalysts, the hemiboronic acid catalyzed protocol can be performed under ambient conditions. Profiling studies revealed that global reduction proceeds via a rapid initial 1,4-addition, followed by ketone deoxygenation with a rate that is highly silane-dependent.

Supporting Information



Publication History

Received: 17 April 2023

Accepted after revision: 16 May 2023

Article published online:
23 June 2023

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