title: Synthesis of quinolines and naphthyridines via catalytic retro-aldol reaction of β-hydroxyketones with ortho-aminobenzaldehydes or nicotinaldehydes.
abstract: A Cu(i)-catalyzed retro-aldol reaction of β-hydroxyketones with ortho-aminobenzaldehydes and nicotinaldehydes is reported that produces a range of quinolines and naphthyridines with high efficiency and selectivity. This reaction uses β-hydroxyketones as a regiospecific ketone-protected enolate source via copper-catalyzed retro-aldol Cα-Cβbond cleavage. The in situ generated copper enolate undergoes kinetically favorable cyclization with ortho-amino aryl aldehydes to produce quinolines and naphthyridines in a chemo- and regioselective manner. The mild and weakly basic reaction conditions also suppress possible side reactions of benzaldehydes under strongly basic conditions, resulting in improved reaction yields.
authors.affiliation: The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, China. slzhang@jiangnan.edu.cn.
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, China. slzhang@jiangnan.edu.cn.
authors.forename: Zhu-Qin
authors.initials: ZQ
authors.lastname: Deng