822-86-6Relevant articles and documents
The Electrochemical cis-Chlorination of Alkenes
Strehl, Julia,Fastie, Cornelius,Hilt, Gerhard
supporting information, p. 17341 - 17345 (2021/10/23)
The first example for the electrochemical cis-dichlorination of alkenes is presented. The reaction can be performed with little experimental effort by using phenylselenyl chloride as catalyst and tetrabutylammoniumchloride as supporting electrolyte, which also acts as nucleophilic reagent for the SN2-type replacement of selenium versus chloride. Cyclic voltammetric measurements and control experiments revealed a dual role of phenylselenyl chloride in the reaction. Based on these results a reaction mechanism was postulated, where the key step of the process is the activation of a phenylselenyl chloride-alkene adduct by electrochemically generated phenylselenyl trichloride. Like this, different aliphatic and aromatic cyclic and acyclic alkenes were converted to the dichlorinated products. Thereby, throughout high diastereoselectivities were achieved for the cis-chlorinated compounds of >95 : 5 or higher.
Dichlorination of olefins with diphenyl sulfoxide/oxalyl chloride
Ding, Rui,Huang, Shuai,Wang, Qiyi,Liu, Yongguo,Sun, Baoguo,Tian, Hongyu
supporting information, p. 2319 - 2330 (2020/07/03)
The combination of diphenyl sulfoxide and oxalyl chloride was used to accomplish the dichlorination of olefins, in which chlorodiphenylsulfonium salt generated in situ was proposed to be the real active species as a chloronium ion source.
Effective bromo and chloro peroxidation catalysed by tungsten(vi) amino triphenolate complexes
Badetti, Elena,Romano, Francesco,Marchiò, Luciano,Ta?kesenlio?lu, Sara,Da?tan, Arif,Zonta, Cristiano,Licini, Giulia
, p. 14603 - 14608 (2016/09/28)
Amino triphenolate tungsten(vi) complexes have been prepared and they proved to be efficient catalysts in haloperoxidation reactions using hydrogen peroxide as a terminal oxidant and inorganic sources of halides. In particular, interesting results have been obtained in the challenging chloroperoxidation reactivity (catalyst loading down to 0.05% with TONs up to 900). A comparison among three different metal complexes bearing the same ligand (vanadium(v), molybdenum(vi) and tungsten(vi)) showed much better performances of the last complex both on bromo and chloro peroxidations.
Organoselenium-catalyzed vicinal dichlorination of unsaturated phosphonates
Zeng, Xianghua,Gong, Chunhua,Zhang, Junyong,Xie, Jingli
supporting information, p. 7866 - 7871 (2016/09/12)
Diphenyl diselenide (PhSeSePh) was effective as a pre-catalyst for the vicinal dichlorination of α,β-unsaturated phosphonates with sulfuryl chloride. The reaction conditions were mild and the desired products were formed in up to 93% yield and moderate diastereoselectivity (10:1). The important diphenylselenium dichloride intermediate was obtained and characterized by X-ray crystallography.
Vicinal dichlorination of olefins using NH4Cl and oxone
Swamy, Peraka,Reddy, Marri Mahender,Kumar, Macharla Arun,Naresh, Mameda,Narender, Nama
, p. 251 - 257 (2014/03/21)
A mild and efficient protocol for the preparation of 1,2-dichloroalkane derivatives from olefins using NH4Cl and Oxone at room temperature is described. A variety of terminal, internal, and cyclic alkenes reacted smoothly to give the corresponding dichlorinated products in good to excellent yields. Moreover, 1,2-disubstituted symmetrical and unsymmetrical olefins dichlorinated with moderate to excellent diastereoselectivity. This method precludes the use of acidic additives and transition metals in the synthesis of vicinal dichlorides.
Pyridine-assisted chlorinations and oxidations by palladium(IV)
McCall, A. Scott,Kraft, Stefan
scheme or table, p. 3527 - 3538 (2012/06/16)
The reactivity of the bis-NHC complex LPdIVCl4 (L = κ2-[R-NHCCH2NHC-R] with R = C14H 29) in chlorinations and oxidations of organic substrates was considerably increased in the presence of pyridine. For alkene chlorinations, this effect was due to the in situ formation of highly reactive LPd IVCl3(py)+, which was able to transfer Cl + to the C=C bond in a ligand-mediated process (devoid of π complexation), which did not require py dissociation. The enhanced reactivity in the presence of pyridine also extended to the oxidation of secondary and benzylic alcohols under mild conditions in a reaction where py served as a base, broadening the known scope of reactivity for PdIV complexes. LPdIVCl3(py)+ could be formed from Cl -/py exchange or from the oxidation of LPdIICl(py) + by Cl2. Taking advantage of the enhanced reactivities that pyridine coordination imparted on both PdII and PdIV complexes allowed for the catalytic chlorination of styrene with LPd IVCl4 as a sacrificial oxidant, thereby establishing the principal feasibility of PdII/PdIV catalyses that obviates PdII activations of the substrate.
Organocatalysis as a safe practical method for the stereospecific dibromination of unsaturated compounds
Hernandez-Torres, Gloria,Tan, Bin,Barbas, Carlos F.
supporting information; experimental part, p. 1858 - 1861 (2012/06/18)
Organocatalytic stereospecific dibromination of a wide variety of functionalized alkenes was achieved using a stable, inexpensive halogen source, 1,3-dibromo 5,5-dimethylhydantoin, and a simple thiourea catalyst at room temperature. The presence of a tertiary amine enhanced the rate of the dibromination reaction, and yields were good in various solvents, including aqueous solvents. The procedure was extended to alkynes and aromatic rings and to dichlorination reactions by using the 1,3-dichloro hydantoin derivative.
Formation of iron(III) meso-chloro-isoporphyrin as a reactive chlorinating agent from oxoiron(IV) porphyrin π-cation radical
Cong, Zhiqi,Kurahashi, Takuya,Fujii, Hiroshi
supporting information; experimental part, p. 4469 - 4472 (2012/04/23)
Iron(III) isoporphyrin, a tautomer of porphyrin with a saturated meso carbon, is one of the isoelectronic forms of oxoiron(IV) porphyrin π-cation radical, which is known as an important reactive intermediate of various heme enzymes. The isoporphyrin has been believed to be incapable of catalyzing oxygenation and oxidation reactions. Here, we report that an oxoiron(IV) porphyrin π-cation radical can be converted to iron(III) meso-chloro- isoporphyrin in the presence of trifluoroacetic acid and chloride ion. More importantly, this study shows the first evidence that iron(III) meso-chloro-isoporphyrin is an excellent reactive agent for chlorinating aromatic compounds and olefins. The results of this study suggest that the mechanism involves electrophilic chlorination of substrate with iron(III) meso-chloro-isoporphyrin.
Bis- N -heterocyclic carbene palladium(IV) tetrachloride complexes: Synthesis, reactivity, and mechanisms of direct chlorinations and oxidations of organic substrates
McCall, A. Scott,Wang, Hongwang,Desper, John M.,Kraft, Stefan
supporting information; experimental part, p. 1832 - 1848 (2011/04/15)
This Article describes the preparation and isolation of novel octahedral CH2-bridged bis-(N-heterocyclic carbene)palladium(IV) tetrachlorides of the general formula LPdIVCl4 [L = (NHC)CH 2(NHC)] from LPdIICl2 and Cl2. In intermolecular, nonchelation-controlled transformations LPdIVCl 4 reacted with alkenes and alkynes to 1,2-dichlorination adducts. Aromatic, benzylic, and aliphatic C-H bonds were converted into C-Cl bonds. Detailed mechanistic investigations in the dichlorinations of alkenes were conducted on the 18VE PdIV complex. Positive solvent effects as well as kinetic measurements probing the impact of cyclohexene and chloride concentrations on the rate of alkene chlorination support a PdIV-Cl ionization in the first step. Product stereochemistry and product distributions from various alkenes also support Cl+-transfer from the pentacoordinated PdIV-intermediate LPdIVCl 3+ to olefins. 1-Hexene/3-hexene competition experiments rule out both the formation of π-complexes along the reaction coordinate as well as in situ generated Cl2 from a reductive elimination process. Instead, a ligand-mediated direct Cl+-transfer from LPd IVCl3+ to the π-system is likely to occur. Similarly, C-H bond chlorinations proceed via an electrophilic process with in situ formed LPdIVCl3+. The presence of a large excess of added Cl- slows cyclohexene chlorination while the presence of stoichiometric amounts of chloride accelerates both PdIV-Cl ionization and Cl+-transfer from LPdIVCl3 +. 1H NMR titrations, T1 relaxation time measurements, binding isotherms, and Job plot analysis point to the formation of a trifurcated Cl-...H-C bond in the NHC-ligand periphery as a supramolecular cause for the accelerated chemical events involving the metal center.
Facile preparation and reactivity of polystyrene-supported (dichloroiodo)benzene: A convenient recyclable reagent for chlorination and oxidation
Chen, Jiang-Min,Zeng, Xiao-Mei,Middleton, Kyle,Zhdankin, Viktor V.
supporting information; experimental part, p. 1952 - 1955 (2011/04/25)
A facile one-pot preparation of polystyrene-supported (dichloroiodo)benzene (loading of -ICl2 up to 1.35 mmol/g) from polystyrene, iodine, and bleach has been developed. This recyclable reagent is useful for efficient chlorination of organic substrates and selective oxidation of various alcohols to the corresponding carbonyl compounds in high yields under mild conditions. The final products are conveniently separated from the polymeric byproduct by simple filtration and isolated in good purity after evaporation of solvent.
