Synthesis 2019; 51(10): 2191-2197
DOI: 10.1055/s-0037-1612250
paper
© Georg Thieme Verlag Stuttgart · New York

Chemoselective Intermolecular Cross-Benzoin Reaction of Aliphatic Aldehydes and Isatins via N-Heterocyclic Carbene Catalysis

Haojie Ji
,
Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. of China   Email: jfxu@zstu.edu.cn
,
Hongjun Ren
› Author Affiliations
We gratefully acknowledge the National Natural Science Foundation of China (Grant No. 21602203), the Natural Science Foundation of Zhejiang Province (Grant No. LQ16B020001), as well as the Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology of Zhejiang Sci-Tech University for financial support.
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Publication History

Received: 22 November 2018

Accepted after revision: 17 January 2019

Publication Date:
19 February 2019 (online)


Abstract

An N-heterocyclic carbene (NHC)-catalyzed chemoselective intermolecular cross-benzoin reaction of aliphatic aldehydes with isatins is developed, affording biologically important 3-substituted 3-hydroxyoxindoles (on gram scale) in moderate to good yields (46–90%). The employment of a morpholinone-derived pentafluorophenyl-substituted triazolium salt as the electron-deficient NHC pre-catalyst is essential to make the reaction go through the cross-benzoin reaction pathway rather than the hydroacylation reaction pathway.

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