- Direct Oxidation of Aryl Malononitriles Enabling a Copper-Catalyzed Intermolecular Alkene Carbochlorination
-
A copper-catalyzed carbochlorination of alkenes with aryl malononitriles and chloride is disclosed. This net oxidative transformation proceeds with activated and unactivated alkenes with moderate to excellent yields. Mechanism experiments suggest addition
- Basnet, Prakash,Hong, Gang,Hendrick, Charles E.,Kozlowski, Marisa C.
-
-
Read Online
- Continuous Flow Organocatalytic Chlorination of Alkenes
-
A regioselective anti-dichlorination and allylic chlorination of isolated double bonds is described. Such chlorination reactions benefit from a combination of methyl phenyl sulfoxide and TMSCl. The method has been appropriately adjusted to fit the continuous flow technology requirements, aiming to a broader industrial implementation for the synthesis of pharmaceutically important compounds. Towards the same direction, a catalytic protocol has been developed, using sub-stoichiometric amount of sulfoxide and environmentally friendly H2O2 as the stoichiometric oxidant, with comparable efficacy.
- Gallos, John K.,Iordanidis, Nicolaos S.,Koftis, Theocharis V.,Stathakis, Christos I.,Zografos, Alexandros L.
-
supporting information
p. 5058 - 5062
(2021/09/28)
-
- Merging shuttle reactions and paired electrolysis for reversible vicinal dihalogenations
-
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.
- Dong, Xichang,Roeckl, Johannes L.,Waldvogel, Siegfried R.,Morandi, Bill
-
-
- Difunctionalization of Alkenes Using 1-Chloro-1,2-benziodoxol-3-(1H)-one
-
Difunctionalization of alkenes with 1-chloro-1,2-benziodoxol-3-(1H)-one (1) was investigated. Various additional nucleophiles were tested, and oxychlorination, dichlorination, azidochlorination, chlorothiocyanation, and iodoesterfication were demonstrated. The oxychlorination product was obtained efficiently when the reaction was operated in water. Dichlorination occurred in the presence of a Lewis basic promoter, such as 4-phenylpyridine N-oxide, as an additive. The reaction with in situ-generated azido anion afforded azidochlorinated compounds with a chlorine atom at the terminal position, while the reaction with trimethylsilyl isothiocyanate produced chlorothiocyanation adducts with a chlorine atom at the benzylic position. On the other hand, when 1 was treated with tetra-n-butylammonium iodide prior to the addition of alkenes, only iodoesterification occurred selectively. These mild reactions enable convenient site-selective difunctionalizations of substrates having two alkene moieties. NMR experiments suggested that the electrophilic reactive species in each reaction varied depending on the nature of the added nucleophile.
- Egami, Hiromichi,Yoneda, Takahiro,Uku, Minako,Ide, Takafumi,Kawato, Yuji,Hamashima, Yoshitaka
-
p. 4020 - 4030
(2016/06/09)
-
- Rasta resin-triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions
-
Heterogeneous polymer-supported triphenylphosphine oxides based on the rasta resin architecture have been synthesized, and applied as reagent precursors in a wide range of halogenation reactions. The rasta resin-triphenylphosphine oxides were reacted with either oxalyl chloride or oxalyl bromide to form the corresponding halophosphonium salts, and these in turn were reacted with alcohols, aldehydes, aziridines and epoxides to form halogenated products in high yields after simple purification. The polymersupported triphenylphosphine oxides formed as a byproduct during these reactions could be recovered and reused numerous times with no appreciable decrease in reactivity.
- Xia, Xuanshu,Toy, Patrick H.
-
p. 1397 - 1405
(2014/07/22)
-