24641-30-3Relevant articles and documents
Asymmetric Synthesis of Hydroquinolines with α,α-Disubstitution through Organocatalyzed Kinetic Resolution
Chen, Yunrong,Zhu, Chaofan,Guo, Zheng,Liu, Wei,Yang, Xiaoyu
supporting information, p. 5268 - 5272 (2021/02/05)
The first kinetic resolution of hydroquinoline derivatives with α,α-disubstitution has been achieved through asymmetric remote aminations with azodicarboxylates enabled by chiral phosphoric acid catalysis. Mechanistic studies suggest a monomeric catalyst pathway proceeding through rate- and enantio-determining electrophilic attack promoted by a network of attractive non-covalent interactions between the substrate and catalyst. Facile subsequent removal and transformations of the newly introduced hydrazine moiety enable these protocols to serve as powerful tools for asymmetric synthesis of N-heterocycles with α,α-disubstitution.
Modular Access to Spiro-dihydroquinolines via Scandium-Catalyzed Dearomative Annulation of Quinolines with Alkynes
Lou, Shao-Jie,Luo, Gen,Yamaguchi, Shigeru,An, Kun,Nishiura, Masayoshi,Hou, Zhaomin
supporting information, p. 20462 - 20471 (2021/12/03)
The catalytic enantioselective construction of three-dimensional molecular architectures from planar aromatics such as quinolines is of great interest and importance from the viewpoint of both organic synthesis and drug discovery, but there still exist many challenges. Here, we report the scandium-catalyzed asymmetric dearomative spiro-annulation of quinolines with alkynes. This protocol offers an efficient and selective route for the synthesis of spiro-dihydroquinoline derivatives containing a quaternary carbon stereocenter with an unprotected N-H group from readily accessible quinolines and diverse alkynes, featuring high yields, high enantioselectivity, 100% atom-efficiency, and broad substrate scope. Experimental and density functional theory studies revealed that the reaction proceeded through the C-H activation of the 2-aryl substituent in a quinoline substrate by a scandium alkyl (or amido) species followed by alkyne insertion into the Sc-aryl bond and the subsequent dearomative 1,2-addition of the resulting scandium alkenyl species to the C=N unit in the quinoline moiety. This work opens a new avenue for the dearomatization of quinolines, leading to efficient and selective construction of spiro molecular architectures that were previously difficult to access by other means.
Visible-Light-Mediated Oxidative Cyclization of 2-Aminobenzyl Alcohols and Secondary Alcohols Enabled by an Organic Photocatalyst
Xu, Jing-Xiu,Pan, Nan-Lian,Chen, Jia-Xi,Zhao, Jin-Wu
, p. 10747 - 10754 (2021/08/16)
This paper describes a visible-light-mediated oxidative cyclization of 2-aminobenzyl alcohols and secondary alcohols to produce quinolines at room temperature. This photocatalytic method employed anthraquinone as an organic small-molecule catalyst and DMSO as an oxidant. According to this present procedure, a series of quinolines were prepared in satisfactory yields.
