Aerobic α,β-C(sp3)-H Bond Difunctionalization and C-N Bond Cleavage of Triethylamine: Difunctional Ammonium Iodide Enabling the Regioselective Synthesis of 4-Arylpyrimido[1,2- b]indazoles

Qinghe Gao; Xinya Han; Peiyuan Tong; Zhiang Zhang; Haotian Shen; Yanrong Guo; Suping Bai

doi:10.1021/acs.orglett.9b02218

Aerobic α,β-C(sp³)-H Bond Difunctionalization and C-N Bond Cleavage of Triethylamine: Difunctional Ammonium Iodide Enabling the Regioselective Synthesis of 4-Arylpyrimido[1,2- b]indazoles

Org Lett. 2019 Aug 2;21(15):6074-6078. doi: 10.1021/acs.orglett.9b02218. Epub 2019 Jul 18.

Authors

Qinghe Gao¹, Xinya Han², Peiyuan Tong¹, Zhiang Zhang¹, Haotian Shen¹, Yanrong Guo², Suping Bai¹

Affiliations

¹ School of Pharmacy , Xinxiang Medical University , Xinxiang , Henan 453003 , P. R. China.
² School of Chemistry and Chemical Engineering , Anhui University of Technology , Maanshan , Anhui 243002 , P. R. China.

PMID: 31318561
DOI: 10.1021/acs.orglett.9b02218

Abstract

A novel method for the regioselective synthesis of 4-arylpyrimido[1,2-b]indazoles has been developed via the dual C(sp³)-H bond functionalization and C-N bond cleavage of triethylamine. The elusive acyclic enamine intermediates are effectively in situ generated and captured by aromatic aldehydes to form a wide array of tricyclic products from 3-aminoindazoles under the NH₄I-mediated aerobic oxidative conditions. This reaction features easily available feedstock, green and economic conditions, and valuable products.

Publication types

Research Support, Non-U.S. Gov't