Phosphine-Mediated Sequential [2+4]/[2+3] Annulation to Construct Pyrroloquinolines

Junhui Lin; Yannan Zhu; Wei Cai; You Huang

doi:10.1021/acs.orglett.1c04388

Phosphine-Mediated Sequential [2+4]/[2+3] Annulation to Construct Pyrroloquinolines

Org Lett. 2022 Mar 4;24(8):1593-1597. doi: 10.1021/acs.orglett.1c04388. Epub 2022 Feb 18.

Authors

Junhui Lin¹, Yannan Zhu¹, Wei Cai¹, You Huang¹

Affiliation

¹ State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.

PMID: 35179034
DOI: 10.1021/acs.orglett.1c04388

Abstract

A domino [2+4]/[2+3] sequential annulation reaction of MBH carbonates with N-unprotected indoles has been developed to provide various pyrroloquinoline derivatives in ≤94% yield and 20:1 dr. The reaction could be either mediated by stoichiometric PCy₃ or catalyzed by R₃PO via P^III/P^V═O redox cycling in the presence of phenylsilane. This method assembles polycyclic 1,7-fused indoles in one step diastereoselectively.