Synlett 2023; 34(11): 1230-1234
DOI: 10.1055/a-2030-6874
letter
Special Edition Thieme Chemistry Journals Awardees 2022

Lewis Acid Catalyzed [4+1] Cycloaddition of o-Quinone Methides and Isocyanides: Mild and Efficient Synthesis of 3-Aryl-2-aminobenzofurans

Cun Yang
,
Yanze Li
,
Qiwen Huang
,
Xinyao Li
We thank the National Natural Science Foundation of China (No. 22101168) and Shanghai Pujiang Talent Scholar (No. 21PJ1403700) for financial support.


Dedicated to the 100th anniversary of Shanghai University

Abstract

We herein report a mild and efficient synthesis of 3-aryl-2-aminobenzofurans by Lewis acid catalyzed [4+1] cycloaddition of in situ generated o-quinone methides and isocyanides. Compared with the well-known methods, the current reactions are carried out under mild conditions and feature wide substrate scope in high yields at ambient temperature at catalyst loadings as low as 1 mol%. DFT calculations show dehydration as the rate-determining step, a stepwise [4+1] cycloaddition process, and the Lewis acid as dual roles in accelerating dehydration and cycloaddition reaction.

Supporting Information



Publication History

Received: 29 November 2022

Accepted after revision: 08 February 2023

Accepted Manuscript online:
08 February 2023

Article published online:
02 March 2023

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