NBS-Promoted Synthesis of Thiocyanated Aminomaleimides and Site-Selective Intramolecular Cyclization Access to 1,4-Benzothiazepines via S-CN Bond Cleavage

Qi Yang; Shuntao Huang; Lu Yin; Zhuoyu Wang; Xuebing Chen; Chao Huang

doi:10.1021/acs.joc.3c02607

NBS-Promoted Synthesis of Thiocyanated Aminomaleimides and Site-Selective Intramolecular Cyclization Access to 1,4-Benzothiazepines via S-CN Bond Cleavage

J Org Chem. 2024 Apr 19;89(8):5266-5276. doi: 10.1021/acs.joc.3c02607. Epub 2024 Apr 9.

Authors

Qi Yang^{1

2}, Shuntao Huang¹, Lu Yin¹, Zhuoyu Wang¹, Xuebing Chen², Chao Huang¹

Affiliations

¹ National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, School of Chemistry and Environment, Yunnan Minzu University, Kunming 650500, P.R. China.
² School of Chemistry and Resource Engineering, Honghe University, Mengzi 661199, P.R. China.

PMID: 38592168
DOI: 10.1021/acs.joc.3c02607

Abstract

A transition metal-free concise and efficient protocol for the synthesis of thiocyanated aminomaleimides and benzo[e][1,4]thiazepine derivatives has been developed. The method involves an initial α-C-H thiocyanation of aminomaleimides with KSCN and TEMPO-mediated tandem S-CN bond cleavage/intramolecular cyclization substitution processes, which enables the formation of seven-membered S/N-heterocycles. This synthetic strategy provides a reliable method for the synthesis of biologically interesting benzo[e][1,4]thiazepine derivatives by using KSCN as sulfur sources as well as expands the application of enaminones thiocyanation reactions in heterocycles synthesis.