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.
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.
Iodine(<scp>iii</scp>)-mediated intramolecular sulfeno- and selenofunctionalization of β,γ-unsaturated tosyl hydrazones and oximes
作者:Jing-Miao Yu、Chun Cai
DOI:10.1039/c7ob02892j
日期:——
A cascade radical cyclization/sulfenylation or selenylation of β,γ-unsaturatedhydrazones and oximes was realized under mild conditions with phenyliodine(III) diacetate (PIDA) as the sole oxidant, leading to the construction of diversely functionalized heteroatom-containing pyrazoline and isoxazoline derivatives. This metal-free radical process is suggested to encompass a sequential C–N/O and C–S/Se
Photocatalytic Generation of N-Centered Hydrazonyl Radicals: A Strategy for Hydroamination of β,γ-Unsaturated Hydrazones
作者:Xiao-Qiang Hu、Jia-Rong Chen、Qiang Wei、Feng-Lei Liu、Qiao-Hui Deng、André M. Beauchemin、Wen-Jing Xiao
DOI:10.1002/anie.201406491
日期:2014.11.3
photocatalytic generation of N‐centered hydrazonyl radicals has been accomplished for the first time. This approach allows efficient intramolecular addition of hydrazonyl radical to terminal alkenes, thus providing hydroamination and oxyamination products in good yields. Importantly, the protocol involves deprotonation of an NH bond and photocatalytic oxidation to an N‐centered radical, thus obviating
A mild and highly efficient Cu‐catalyzed cascade cyclization/thiocyanation of unactivated alkenes bearing hydrazones has been developed. A broad range of SCN‐substituted pyrazolines have been readily obtained in good to excellent yields with commercially available and very cheap Cu(acac)2 and NH4SCN. This present method provides a rapid, facile, and practical access to valuable pyrazolines with the