The base-promoted isomerization of aziridines to allyl amines is still an almost unknown reaction. However, the use of superbasic reagents has shown to be able to promote a regio- and stereoselective conversion of monocyclic and bicyclic sulfonyl aziridines. Moreover, the use of alkoxy substituted aziridines opens new routes to non-natural alpha- and beta-amino acids. (C) 2002 Elsevier Science Ltd. All rights reserved.
(t-BuOI) was found to be a powerful reagent for synthesis of aziridines from olefins and sulfonamides. The aziridination of olefins was achieved by using sulfonamides with t-BuOI. Our preliminary findings represent the example of metal-free aziridination of olefins with readily accessible sulfonamides as a nitrogensource.
Novel organic-solvent-free aziridination of olefins: Chloramine-T–I2 system under phase-transfer catalysis conditions
作者:Daisuke Kano、Satoshi Minakata、Mitsuo Komatsu
DOI:10.1039/b104940m
日期:2001.11.29
A variety of olefins could be aziridinated successfully by employing iodine-catalysed aziridination in water with a catalytic amount of a quaternary ammonium salt. Furthermore, the larger-scale process of styrene aziridination gives a highly pure aziridine in good yield via simple work-up.
Iodine was found to be an efficient catalyst for the aziridination of alkenes utilizing Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source. For example, when two equivalents of styrene were added to Chloramine-T in the presence of a catalytic amount of iodine in a 1 : 1 solvent mixture of acetonitrile and neutral buffer, the corresponding aziridine 1 was obtained in 91% yield. The reaction could be applied to other acyclic and cyclic alkenes such as 1-octene and cyclohexene. The aziridination of p-substituted styrene derivatives 2-5 with Chloramine-T showed that electron-rich alkenes reacted faster than electron-poor ones. Several Chloramine-T analogs were also examined and were found to give the corresponding aziridines 8-10 in only moderate yields. (C) 1998 Elsevier Science Ltd. All rights reserved.