New methods for the preparations of 2-aryl aziridines, α-imido styrenes, and allyl amines from olefins via diphenylvinylsulfonium triflates

Hiroyuki Yamanaka,Teruaki Mukaiyama,Jun-Ichi Matsuo,Asahi Kawana,G S R Subba Rao

doi:10.3998/ark.5550190.0005.306

Abstract

Reactions of diphenylvinylsulfonium triflates with primary amines and imides afforded 2- arylaziridines and α-imidostyrenes, respectively. These products were also obtained from styrenes in one vessel without isolation of the intermediate sulfonium salts. In addition, 1,1- disubstituted and trisubstituted alkenes were converted into allylamines via isomerization of initially formed vinylsulfonium salts to allylsulfonium salts in the presence of primary or secondary amines.

Highlights

Vinylphosphonium and vinylsulfonium salts are known as good Michael acceptors that undergo addition reactions with various nucleophiles
We recently reported three unique reactions of diphenylvinylsulfonium triflates 1 in a preliminary form as shown in Scheme 1: new synthetic approaches to (i) 2-arylaziridines 25 and (ii) α-imidostyrenes 36 from styrene derivatives via 1, and (iii) allylamines 57 from alkenes via unusual conversion of 1 to allylsulfonium salts 4
Preparation of diphenylvinylsulfonium triflates Diphenylvinylsulfonium triflates were prepared according to Nenajdenko's procedure.[8]

Summary

Introduction

Vinylphosphonium and vinylsulfonium salts are known as good Michael acceptors that undergo addition reactions with various nucleophiles. The former salts have been widely used as precursors of phosphonium ylides in the syntheses of heterocyclic compounds[1] and allylamines[2] via initial Michael addition and subsequent Wittig reaction (Schweizer reaction). Synthetic applications of vinylsulfonium salts are limited to a few reactions such as cyclopropanation reactions with active methylene compounds[3] or enolates[4] in which dimethylvinylsulfonium salts are frequently used and act as ethylene transfer reagents by liberating dimethyl sulfide. The result of this methyl transfer reaction prompted us to study on reactions of diphenylvinylsulfonium salts with nitrogen nucleophiles in order to investigate chemical behaviors of the salts. We would like to describe these three reactions in detail

Results and Discussion

Ph 8 Ph

NPht : N

Conclusions