71566-71-7Relevant articles and documents
Merging shuttle reactions and paired electrolysis for reversible vicinal dihalogenations
Dong, Xichang,Roeckl, Johannes L.,Waldvogel, Siegfried R.,Morandi, Bill
, (2021/02/12)
Vicinal dibromides and dichlorides are important commodity chemicals and indispensable synthetic intermediates in modern chemistry that are traditionally synthesized using hazardous elemental chlorine and bromine. Meanwhile, the environmental persistence of halogenated pollutants necessitates improved approaches to accelerate their remediation. Here, we introduce an electrochemically assisted shuttle (e-shuttle) paradigm for the facile and scalable interconversion of alkenes and vicinal dihalides, a class of reactions that can be used both to synthesize useful dihalogenated molecules from simple alkenes and to recycle waste material through retro-dihalogenation. The reaction is demonstrated using 1,2-dibromoethane, as well as 1,1,1,2-tetrachloroethane or 1,2-dichloroethane, to dibrominate or dichlorinate, respectively, a wide range of alkenes in a simple setup with inexpensive graphite electrodes. Conversely, the hexachlorinated persistent pollutant lindane could be fully dechlorinated to benzene in soil samples using simple alkene acceptors.
Catalytic Vicinal Dichlorination of Unactivated Alkenes
Sarie, Jér?me C.,Neufeld, Jessica,Daniliuc, Constantin G.,Gilmour, Ryan
, p. 7232 - 7237 (2019/08/26)
Organocatalytic strategies for the programmed, catalytic oxidation of ?-bonds through regioselective halogenation remain comparatively underdeveloped. The vicinal dichlorination of unactivated alkenes is a pertinent example, where stoichiometric reagents and prefunctionalization steps are often employed. This is surprising given the prominence of the 1,2-dichloro moiety in an array of bioactive natural products of both terrestrial and marine origin. Inspired by Willgerodt's seminal discovery in 1886 that PhICl2 can be generated by passing Cl2(g) through iodobenzene, a catalytic vicinal dichlorination of unactivated alkenes has been designed on the basis of an I(I)/I(III) manifold. In situ generation of p-TolICl2 is achieved using Selectfluor and CsCl. Substrate scope, mechanistic delineation, and preliminary validation of an enantiomeric variant are established. Over a century after the initial discovery of the Willgerodt reagent (PhICl2), an operationally simple, catalytic alternative has been validated.
Electrocatalytic Radical Dichlorination of Alkenes with Nucleophilic Chlorine Sources
Fu, Niankai,Sauer, Gregory S.,Lin, Song
supporting information, p. 15548 - 15553 (2017/11/06)
We report a Mn-catalyzed electrochemical dichlorination of alkenes with MgCl2 as the chlorine source. This method provides operationally simple, sustainable, and efficient access to a variety of vicinally dichlorinated compounds. In particular, alkenes with oxidatively labile functional groups, such as alcohols, aldehydes, sulfides, and amines, were transformed into the desired vicinal dichlorides with high chemoselectivity. Mechanistic data are consistent with metal-mediated Cl atom transfer as the predominant pathway enabling dual C-Cl bond formation and contradict an alternative pathway involving electrochemical evolution of chlorine gas followed by Cl2-mediated electrophilic dichlorination.
