Synthesis 2024; 56(09): 1381-1392
DOI: 10.1055/s-0043-1763679
paper

Stereoselective Synthesis of 3,4-Dihydrobenzofuro[3,2-b]pyridin-2(1H)-ones Enabled by Pd/Chiral Isothiourea Relay Catalysis

Mostafa Sayed
a   Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
b   Chemistry Department, Faculty of Science, New Valley University, El-Kharja 72511, Egypt
,
Zhipeng Shi
a   Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
,
Tao Fan
a   Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
,
Hong-Cheng Shen
a   Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
,
Zhi-Yong Han
a   Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
› Author Affiliations
We are grateful for the financial support from NSFC (Grants 21831007, 21971231).


Abstract

A highly enantioselective [4+2] cyclization of azadienes with ketene in situ generated from Pd-catalyzed carbonylation of benzyl bromides, is established through Pd/chiral isothiourea relay catalysis. The key in this transformation is the formation of a C1-ammonium enolate from the in situ generated ketene and a chiral isothiourea catalyst, which subsequently undergoes a formal [4+2] reaction, leading to 3,4-dihydrobenzofuro[3,2-b]pyridine derivatives in high yields and excellent levels of stereoselectivity.

Supporting Information



Publication History

Received: 27 November 2023

Accepted after revision: 22 January 2024

Article published online:
13 February 2024

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