Issue 4, 2017

Selective uni- and bidirectional homologation of diborylmethane

Abstract

Diborylmethane can be homologated uni- and bidirectionally by using enantiomerically pure lithium-stabilized carbenoids to give 1,2- and 1,3-bis(boronic esters), respectively, in good yield and with excellent levels of enantio- and diastereoselectivity. The high sensitivity of the transformation to steric hindrance enables the exclusive operation of either manifold, effected through the judicious choice of the type of carbenoid, which can be a sparteine-ligated or a diamine-free lithiated benzoate/carbamate. The scope of the 1,2-bis(boronic esters) so generated is complementary to that encompassed by the asymmetric diboration of alkenes, in that primary–secondary and primary–tertiary 1,2-bis(boronic esters) can be prepared with equally high levels of selectivity and that functional groups, such as terminal alkynes and alkenes, are tolerated. Methods for forming C2-symmetric and non-symmetrical anti and syn 1,3-bis(boronic esters) are also described and represent a powerful route towards 1,3-functionalized synthetic intermediates.

Graphical abstract: Selective uni- and bidirectional homologation of diborylmethane

Supplementary files

Article information

Article type
Edge Article
Submitted
05 Dec 2016
Accepted
19 Jan 2017
First published
09 Feb 2017
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2017,8, 2898-2903

Selective uni- and bidirectional homologation of diborylmethane

D. J. Blair, D. Tanini, J. M. Bateman, H. K. Scott, E. L. Myers and V. K. Aggarwal, Chem. Sci., 2017, 8, 2898 DOI: 10.1039/C6SC05338F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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