Manganese-Catalyzed Regioselective Hydroboration of Quinolines via Metal-Ligand Cooperation  

作　　者：Yujie Wang Hengxu Li Haobo Yang Mingjie Fan Qiang Liu 

机构地区：[1]Center of Basic Molecular Science(CBMS),Department of Chemistry,Tsinghua University,Beijing 100084

出　　处：《CCS Chemistry》2024年第6期1535-1546,共12页中国化学会会刊（英文）

基　　金：the National Key R&D Program of China(grant no.2021YFF0701600);the National Natural Science Foundation of China(grant no.22225103);Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs,Shanghai Jiao Tong University,and the China Postdoctoral Science Foundation(grant nos.2020M680021 and 2021T140366),which was greatly appreciated.

摘　　要：Selective reduction of readily available N-heteroarenes is important in both organic synthesis and chemical biology.Herein,we describe ligand-controlled regiodivergent hydroboration of quinolines using well-defined amido-manganese catalysts,with an emphasis on the rarely reported 1,4-regioselectivity.Mechanistic studies showed that 1,2-hydroboration of quinoline was kinetically favorable and reversible,whereas 1,4-hydroboration was under thermodynamic control.Using a 1-methyimidazolebased pincer amido-manganese complex as the catalyst,cooperative C-H…N andπ…πnoncovalent interactions between the 1-methyimidazole moiety and quinoline substrates enabled kinetic accessibility of 1,4-hydroboration,giving thermodynamically favored 1,4-hydroborated quinolines as the major products.On this basis,Mn-catalyzed 1,4-hydroboration of a series of substituted quinolines proceeded smoothly in high yields.A high turnover number of 2500 was achieved in this reaction with satisfying regioselectivity.This transformation could be further applied to the C3-selective functionalization of quinolines,highlighting the synthetic utility of this methodology.In contrast,using a pyridine-based pincer amido-manganese complex as the catalyst,which lacked the C-H…N interaction,the free-energy barrier for 1,4-hydroboration significantly increased through a N-B…N interaction between the“HMn-NB”species and quinoline,resulting in the kinetically favored 1,2-hydroboration product with excellent regioselectivity.

关 键 词：catalytic hydroboration N-heteroarenes regioselectivity manganese catalysis metal-ligand cooperation 

分 类 号：O62[理学—有机化学]