Synthesis 2023; 55(06): 989-999
DOI: 10.1055/a-1975-4377
paper

Palladium-Catalyzed Double Carbopalladation/syn-Insertion Cascade toward a Pragmatic Synthesis of Aminated Polyheterocyclic 1,2-Benzothiazepine 1-Oxides

Zhigang Huang
a   College of Chemistry & Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, P. R. of China
,
Longji Dai
a   College of Chemistry & Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, P. R. of China
,
Zhiyuan Chen
a   College of Chemistry & Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, P. R. of China
b   Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou 310015, P. R. of China
› Author Affiliations
We thank the National Natural Science Foundation of China (No. 21961015) and the Natural Science Foundation of Jiangxi Province (No. 20202ACBL203005) for financial support.


Abstract

A palladium-catalyzed tandem cyclization reaction was developed, which offers a pragmatic synthesis of aminated tetracyclic 1,2-benzothiazepine 1-oxides bearing a highly fused medium-sized cyclic unit. An acetyl (Ac) group was found to be the optimal protecting group for sulfoximines to reduce the nucleophilic ability of the N atom, thus efficiently suppressing the formation of intramolecular 5-exo-dig cyclization side products. The transformation proceeds through a double syn-carbopalladation/annulation sequence to construct the rigid tetracyclic carbo-heterocyclic framework with excellent chemoselectivity and regioselectivity.

Supporting Information



Publication History

Received: 21 August 2022

Accepted after revision: 09 November 2022

Accepted Manuscript online:
09 November 2022

Article published online:
29 November 2022

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