2-Chloropyridazin-3(2<i>H</i>)-ones as Electrophilic Chlorinating Agents: Effective α-Chlorination of Active Methylene/Methine Compounds
作者:Yong-Jin Yoon、Yong-Dae Park、Jeum-Jong Kim、Su-Dong Cho、Sang-Gyeong Lee、J. Russell Falck
DOI:10.1055/s-2005-861845
日期:——
2,4,5-Trichloro- (2a) and 2,4-dichloro-5-methoxypyridazin-3(2H)-one (2b) are novel electrophilic chlorinating agents. α-Chlorination of activemethylene/methinecompounds with 2 in the presence of either Lewis or protonicacids in dichloromethane (for Lewis acid) or water (for protonic acid or none) at room temperature gave also selectively α-monochlorides and/or a,a-dichlorides in good to excellent
Solvent-free preparation of α,α-dichloroketones with sulfuryl chloride
作者:Dewei Tu、Juan Luo、Wengao Jiang、Qiang Tang
DOI:10.1016/j.tetlet.2021.153335
日期:2021.9
An efficient and facile method is reported for the synthesis of a series of α,α-dichloroketones. The direct dichlorination of methyl ketones and 1,3-dicarbonyls using an excess amount of sulfuryl chloride affords the corresponding -dichloro compounds in moderate to excellent yields. Moreover, the protocol features high yields, broad substrate scope, and simple reaction conditions without using any
A Chlorinating Reagent: N-chloro-N-methoxybenzene Sulfonamide
作者:Xiaoqiu Pu、Qingwei Li、Zehai Lu、Xianjin Yang
DOI:10.1002/ejoc.201601226
日期:2016.11
Abstract: A structurally simple and reactive chlorinatingreagent,N-chloro-N-methoxybenzenesulfonamide, was conveniently and economically prepared in high yield. 1,3-Diketones, β-keto esters, benzoyl trifluoroacetones, phenols, anisoles, heteroarenes andaromatic amines were chlorinated with it, obtaining chlorinated products in good to high yields.
Conversion of Nucleophilic Halides to Electrophilic Halides: Efficient and Selective Halogenation of Azinones, Amides, and Carbonyl Compounds Using Metal Halide/Lead Tetraacetate
作者:Su-Dong Cho、Yong-Jin Yoon、Jeum-Jong Kim、Deok-Heon Kweon、Ho-Kyun Kim、Sang-Gyeong Lee
DOI:10.1055/s-2006-926224
日期:——
AlCl 3 /Pb(OAc) 4 and ZnBr 2 /Pb(OAc) 4 are efficient electrophilic N- and α-C-halogenating agents. A variety of azinones, amides and carbonylcompounds were chemoselectively and regioselectively N-, or α-C-halogenated in good to excellent yield using AlCl 3 /Pb(OAc) 4 and ZnBr 2 /Pb(OAc) 4 in acetonitrile.
A new method for the α,α-dichlorination of β-keto esters using Oxone/aluminum trichloride mixture in aqueous medium has been developed. This useful process has also been applied successfully for the dichlorination of 1,3-diketones. The dichlorinated compounds have been produced in one step, high yields, and short reaction times.