Synthesis of indolo- and benzothieno[3,2-c]quinolines via POCl3 mediated tandem cyclization of o-alkynylisocyanobenzenes derived from o-alkynyl-N-phenylformamides

Uppalabat, Thikhamporn; Tapdara, Anyawan; Khaikate, Onnicha; Worakul, Thanapat; Surawatanawong, Panida; Leowanawat, Pawaret; Soorukram, Darunee; Reutrakul, Vichai; Meesin, Jatuporn; Kuhakarn, Chutima

doi:10.1039/d2nj02791g

Synthesis of indolo- and benzothieno[3,2-c]quinolines via POCl3 mediated tandem cyclization of o-alkynylisocyanobenzenes derived from o-alkynyl-N-phenylformamides

Author(s)

Uppalabat, Thikhamporn

Tapdara, Anyawan

Khaikate, Onnicha

Worakul, Thanapat

Surawatanawong, Panida

Leowanawat, Pawaret

Soorukram, Darunee

Reutrakul, Vichai

Meesin, Jatuporn

Kuhakarn, Chutima

Date Issued

August 1, 2022

Type

Article

DOI

10.1039/d2nj02791g

Abstract

A synthesis of indolo[3,2-c]quinolines and benzothieno[3,2-c]quinolines has been developed employing o-alkynyl-N-phenylformamide derivatives as the substrates. The reaction proceeded via a tandem process involving POCl3-assisted intramolecular cyclization of the firstly formed o-alkynylisocyanobenzenes, leading to the desired products in moderate to high yields. Furthermore, the reaction is efficient on a gram-scale and the products were structurally modified by amination, Suzuzki-Miyaura reaction and Heck cross-coupling. Photophysical properties of several selected indolo[3,2-c]quinolines were studied by UV-Visible and fluorescence spectroscopy and rationalized using time-dependent DFT calculations.

Citation

New Journal of Chemistry, 46(34), 16333-16340, 2022