Palladium-Catalyzed Direct C-H Functionalization of Indoles with the Insertion of Sulfur Dioxide: Synthesis of 2-Sulfonated Indoles

Tong Liu; Wei Zhou; Jie Wu

doi:10.1021/acs.orglett.7b03365

Palladium-Catalyzed Direct C-H Functionalization of Indoles with the Insertion of Sulfur Dioxide: Synthesis of 2-Sulfonated Indoles

Org Lett. 2017 Dec 15;19(24):6638-6641. doi: 10.1021/acs.orglett.7b03365. Epub 2017 Nov 28.

Authors

Tong Liu¹, Wei Zhou¹, Jie Wu^{1

2}

Affiliations

¹ Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, China.
² State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, China.

PMID: 29182287
DOI: 10.1021/acs.orglett.7b03365

Abstract

A palladium-catalyzed direct C-H bond sulfonylation of indoles with the insertion of sulfur dioxide is achieved through a three-component reaction of 1-(pyridin-2-yl)indoles, DABCO·(SO₂)₂, and aryldiazonium tetrafluoroborates under mild conditions. Diverse 2-sulfonated indoles are generated by using 10 mol % of palladium(II) bromide as the catalyst at room temperature. This synthetic approach is efficient by merging palladium catalysis and insertion of sulfur dioxide via a radical process. 2-Pyrimidinyl can be used as the directing group well as for the C-H bond sulfonylation. Additionally, the directing group can be easily removed.

Publication types

Research Support, Non-U.S. Gov't