Synlett 2023; 34(18): 2181-2186
DOI: 10.1055/a-2106-1461
cluster
Modern Boron Chemistry: 60 Years of the Matteson Reaction

Asymmetric Catalytic Hydroboration of Enol Carbamates Enables an Enantioselective Matteson Homologation

Dmitry M. Kuznetsov
,
Joseph M. Ready
Funding came from the Welch Foundation (I-1612) and the National Institutes of Health (RM1 GM142002).


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Abstract

A rhodium-catalyzed asymmetric hydroboration of enol carbamates yields α-boryl carbamates with a good enantioselectivity. The enol carbamate starting materials can be prepared with moderate Z-selectivity by using a modified Juila olefination; they can then be used as the resulting E/Z mixtures, taking advantage of the faster reactivity of the major Z-isomers in the directed hydroboration. Optically active α-boryl carbamates participate in a Matteson-type homologation with Grignard reagents, in which the O-carbamate is substituted, with high conservation of optical activity, to provide enantioenriched secondary boronic esters.

Supporting Information



Publication History

Received: 10 May 2023

Accepted after revision: 05 June 2023

Accepted Manuscript online:
05 June 2023

Article published online:
26 July 2023

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