Carbazoles from the [4C+2C] Reaction of 2,3-Allenols with Indoles

Binjie Guo; Xin Huang; Chunling Fu; Shengming Ma

doi:10.1002/chem.201604317

Carbazoles from the [4C+2C] Reaction of 2,3-Allenols with Indoles

Chemistry. 2016 Dec 19;22(51):18343-18348. doi: 10.1002/chem.201604317. Epub 2016 Nov 10.

Authors

Binjie Guo¹, Xin Huang¹, Chunling Fu¹, Shengming Ma¹

Affiliation

¹ Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, P.R. China.

PMID: 27726222
DOI: 10.1002/chem.201604317

Abstract

A mild and efficient method using readily available 1-aryl-2,3-allenols and unprotected-N indoles, Au⁺ -catalyzed cyclization, and aromatization to afford the final [4C+2C] products, carbazoles 4, with an excellent selectivity, is reported. The reaction demonstrates excellent regioselectivity and allows the N-H unit to undergo reactivity unprotected. A mechanism involving a spiropolycyclic intermediate has been proposed and synthetic application is also demonstrated.

Keywords: allenes; aromatization; carbazoles; cyclization; indoles.