Green and Facile Synthesis of Spirocyclopentanes Through NaOH-Promoted Chemo- and Diastereo-Selective (3 + 2) Cycloaddition Reactions of Activated Cyclopropanes and Enamides

Xun Zhu; Dingwu Pan; Chengli Mou; Bo Zhou; Lutai Pan; Zhichao Jin

doi:10.3389/fchem.2020.00542

Green and Facile Synthesis of Spirocyclopentanes Through NaOH-Promoted Chemo- and Diastereo-Selective (3 + 2) Cycloaddition Reactions of Activated Cyclopropanes and Enamides

Front Chem. 2020 Jun 26:8:542. doi: 10.3389/fchem.2020.00542. eCollection 2020.

Authors

Xun Zhu¹, Dingwu Pan¹, Chengli Mou², Bo Zhou³, Lutai Pan², Zhichao Jin¹

Affiliations

¹ Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education, Guizhou University, Guiyang, China.
² School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China.
³ R&D Center, Shenzhen AmTech Bioengineering Ltd., Inc., Shenzhen, China.

Abstract

A chemo- and diastereo-selective (3 + 2) cycloaddition reacition between Donor-Acceptor (D-A) cyclopropanes and α,β-unsaturated enamides is developed for efficient access to spiro(cyclopentane-1,3'-indoline) derivatives. Simple, inexpensive and readily available NaOH is used as the sole catalyst for this process. A broad range of D-A cyclopropanes could be used as the C-3 synthons to react with oxindole-derived α,β-unsaturated enamides. The structurally sophisticated spiro(cyclopentane-1,3'-indoline) derivatives bearing up to 3 adjacent chiral centers are afforded in excellent yields as single diastereomers.

Keywords: (3 + 2) cycloaddition; NaOH; donor-acceptor cyclopropane; green; indole derivative; spirocyclopentane.