Iodine-mediated aminosulfonylation of alkenyl sulfonamides with sulfonyl hydrazides: synthesis of sulfonylmethyl piperidines, pyrrolidines and pyrazolines
作者:Zhong-Qi Xu、Wen-Bo Wang、Lin-Chuang Zheng、Lin Li、Lili Duan、Yue-Ming Li
DOI:10.1039/c9ob01847f
日期:——
aminosulfonylation of alkenyl sulfonamides was reported. Using iodine as the catalyst, TBHP as the oxidant, and sulfonyl hydrazides as the sulfonyl radical sources, a variety of sulfonylmethyl piperidines, pyrrolidines and pyrazolines were obtained in moderate to excellent yields.
An asymmetric synthesis of 5-halomethyl pyrazolines and isoxazolines which bear a tertiary stereocenter by catalytic halocyclization of β,γ-unsaturatedhydrazones and ketoximes is described. By using Brønsted acids of anionic chiral Co(III) complexes as catalysts, a variety of chiral 5-halomethyl pyrazolines and isoxazolines were obtained in good yields with high enantioselectivities (up to 99% yield
Ambient-Light-Promoted Perfluoroalkylative Cyclization of β,γ-Unsaturated Hydrazones: Synthesis of Perfluoroalkylated Pyrazolines
作者:Jing-miao Yu、Chun Cai
DOI:10.1002/ejoc.201701201
日期:2017.11.2
An ambient‐light‐promoted, metal‐free strategy for the direct perfluoroalkylativecyclization of β,γ‐unsaturated hydrazones is reported. This radical process has wide functional‐group tolerance, is performed under mild reaction conditions, and is operationally simple. The perfluoroalkylatedpyrazoline products are obtained in good to excellent yields. TMG = 1,1,3,3‐tetramethylguanidine.
applied for the first time to the direct conversion of N−H and O−H bonds into N‐ and O‐centred radicals, enabling a general and selective oxidative radical oxyamination and dioxygenation of various β,γ‐unsaturated hydrazones and oximes. In the reaction, O2 was employed not only as a terminal oxidant but also as the oxygen source. This protocol provided efficient access to the synthesis of various synthetically
Palladium-Catalyzed Aminomethylamination and Aromatization of Aminoalkenes with Aminals via C–N Bond Activation
作者:Lixin Li、Peipei Liu、Yijin Su、Hanmin Huang
DOI:10.1021/acs.orglett.6b03001
日期:2016.11.4
the Pd-catalyzed tandem aminomethylamination/aromatization reaction with aminals via C–N bond activation. This direct and operationally simple protocol provides a fundamentally novel strategy to synthesize aromatic heterocycles from alkenes in the absence of external oxidant and base. Mechanistic studies suggested that aminal not only functioned as an aminomethyl source but also acted as formal oxidant