Enantioselectivity-Switchable Organocatalytic [4 + 2]-Annulation to Access the Spirooxindole-Norcamphor Scaffold

Jing Wang; Xian-Zhou Zheng; Jun-An Xiao; Kai Chen; Hao-Yue Xiang; Xiao-Qing Chen; Hua Yang

doi:10.1021/acs.orglett.0c04164

Enantioselectivity-Switchable Organocatalytic [4 + 2]-Annulation to Access the Spirooxindole-Norcamphor Scaffold

Org Lett. 2021 Feb 5;23(3):963-968. doi: 10.1021/acs.orglett.0c04164. Epub 2021 Jan 22.

Authors

Jing Wang¹, Xian-Zhou Zheng¹, Jun-An Xiao², Kai Chen¹, Hao-Yue Xiang¹, Xiao-Qing Chen¹, Hua Yang¹

Affiliations

¹ College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
² Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning 530001, China.

PMID: 33481615
DOI: 10.1021/acs.orglett.0c04164

Abstract

An organocatalyzed enantiodivergent synthesis of a multifunctionalized spirooxindole-norcamphor scaffold via a [4 + 2]-annulation between cyclicα, β-unsaturated ketone and methylene indolinones has been established. The presence of CaCl₂ in DMF could reverse the enantioselectivity to facilely deliver the enantiomers of the corresponding spirooxindoles. Both enantiomers of the corresponding spirooxindoles were obtained in excellent yield and diastereo-/enantioselectivity by employing one single prolinosulfonamide catalyst.