Download PDF
Synlett 2006(3): 0498-0499  
DOI: 10.1055/s-2006-926262
SPOTLIGHT
© Georg Thieme Verlag Stuttgart · New York

N-Bromosuccinimide - A Selective, Mild Substitute for Bromine

Taraknath Kundu*
Department of Chemistry, Bose Institute, 93/1, A.P.C. Road, ­Kolkata 700 009, India
e-Mail: taraknath_kundu@yahoo.co.uk;
Further Information

Publication History

Publication Date:
06 February 2006 (online)

   Permissions and Reprints All articles of this category

Introduction

N-Bromosuccinimide (NBS) is commercially available but can also be prepared from succinimide by bromination under alkaline conditions. It is used as a mild source of bromine with higher selectivity, primarily due to its ­property of releasing of bromine in a low, steady-state concentration. [1] It is most widely used for benzylic and ­allylic brominations in the presence of a catalytic amount of a free-radical initiator such as benzoyl peroxide or AIBN in CCl4. [2a] However, benzylic bromination in the absence of any free-radical initiator was recently achieved under microwave irradiation (MWI) in solid phase. [2b] The free-radical condition is also reported to bring about Z- to E-alkene isomerisation. [2c] Cook and co-workers demonstrated the regioselectivity of bromination by NBS under different conditions with indoles. [2a] In many instances, NBS has been used as an activator, for example in stereoselective glycosidation, [3a] protection [3b] and deprotection of ketals [3c] or THP ethers, [3d] and in the synthesis of diindolyl­alkanes. [3e] NBS is also widely used as a mild oxidant [4] as well as for oxidative cyclisations. [5] Recently, NBS was used for the mild, regioselective bromination of ­(hetero)aromatics in ionic liquid, [6a] [b] or for α-bromination of carbonyl compounds in the presence of NaHSO4-SiO2, [6c] or TMSOTf. [6d]