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Updated: Apr 10, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Photoinduced Hydrogenative Dearomatization With Homocoupling of Quinolines to Construct Octahydro-4,4'-biquinolines
Mone Suzuki1, Asuha Shimose1, Yuki Nagashima2,3
1Department of Chemical Science and Engineering, Institute of Science Tokyo, Meguro-ku, Tokyo, Japan.
Abstract:
Dearomative functionalization of heteroaromatics has greatly contributed to drug discovery owing to nitrogen-containing three-dimensional (3D) sp3-rich frameworks. However, conventional dearomative functionalization of quinolines affords limited types of tetrahydroquinoline (THQ)-based polycycles. Herein, we present a chemoselective dearomative hydrogenative dearomatization with homocoupling of quinolines into 1,1',2,2',3,3',4,4'-octahydro-4,4'-biquinoline (OHBQ) without any photocatalyst, through boron-mediated photoexcitation using HB(pin) and KOtBu. Experimental and computational mechanistic studies revealed that the thermally induced dearomative hydroboration functionalization proceeds initially, and subsequently the photoexcited boron complex enables an unprecedented homocoupling of 1,2,3,4-THQs, which is challenging in the ground state, to yield the desired OHBQ.
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