Synlett 2019; 30(20): 2203-2208
DOI: 10.1055/s-0039-1690212
synpacts
© Georg Thieme Verlag Stuttgart · New York

[3,3]- and [5,5]-Sigmatropic Rearrangements of Aryl Sulfoxides Using An ‘Assembly/Deprotonation’ Technology

Lei Zhang
,
Mengjie Hu
,
Bo Peng
This work is supported by Zhejiang Normal University and the National Natural Science Foundation of China (Grant No. 21502171).
Further Information

Publication History

Received: 26 August 2019

Accepted after revision: 07 October 2019

Publication Date:
17 October 2019 (online)


Abstract

The redox-neutral ortho-functionalizations of aryl/heteroaryl sulfoxides via interrupted Pummerer processes have been greatly advanced since its discovery by Kita and Padwa in the early 2000s. In this context, we recently developed an ortho-cyanoalkylation of aryl sulfoxides with alkyl nitriles using an ‘assembly/deprotonation’ protocol. The success of the reaction hinges on the independent control of the electrophilic assembly of both coupling partners and subsequent deprotonation of the in situ generated imine sulfonium intermediates. Further [3,3]-sigmatropic rearrangement of the in situ formed ketenimine sulfonium species furnishes ortho-cyanoalkylated aryl sulfides. More recently, we also applied the ‘assembly/deprotonation’ strategy for the development of the [5,5]-sigmatropic rearrangement of aryl sulfoxides with allyl nitriles that allows for para-cyanoalkylation of aryl sulfoxides. The development of these two reactions is described in this Synpacts article.

1 Background

2 [3,3]-Sigmatropic Rearrangement

3 [5,5]-Sigmatropic Rearrangement

4 Conclusion