Chiral NHC-Catalyzed [4+2] Cycloadditions: Highly Diastereo/Enantioselective Access to Spiro[cyclohex-4-ene-1,3'-indoles] and DFT Calculations

Xiaoyu Chen; Siqi Xia; Xiaoru Hu; Guofu Zhong; Limin Yang

doi:10.1002/chem.202203818

Chiral NHC-Catalyzed [4+2] Cycloadditions: Highly Diastereo/Enantioselective Access to Spiro[cyclohex-4-ene-1,3'-indoles] and DFT Calculations

Chemistry. 2023 Apr 21;29(23):e202203818. doi: 10.1002/chem.202203818. Epub 2023 Mar 15.

Authors

Xiaoyu Chen¹, Siqi Xia¹, Xiaoru Hu¹, Guofu Zhong^{1

2}, Limin Yang¹

Affiliations

¹ College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, Zhejiang, 311121, P.R. China.
² Department of Chemistry, Eastern Institute for Advanced Study, Ningbo, Zhejiang, 315200, P.R. China.

PMID: 36638350
DOI: 10.1002/chem.202203818

Abstract

A highly efficient NHC-catalyzed cycloaddition of (E)-alkenylisatins and γ-chloroenals with a broad substrate scope has been developed to provide spiro[cyclohex-4-ene-1,3'-indole] in good yields (up to 99 % yield) with excellent diastereo- and enantioselectivities (up to >20 : 1 d.r., >99 % ee) under mild conditions without the use of metal and additives. Based on computational investigations, the role of the NHC on the diastereo- and enantioselectivity is discussed.

Keywords: DFT calculations; NHC-catalyzed; [4+2] cycloaddition; spiro[cyclohex-4-ene-1,3′-indole].

Abstract

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