951-86-0Relevant articles and documents
Cobalt(salen)-electrocatalyzed conversion of benzotrichloride into tolane. A triply catalytic and overall quintuple electrochemical transformation
Kaufman, Seth A.,Phanijphand, Twan,Fry, Albert J.
, p. 8105 - 8108 (1996)
Electrochemical reduction of a mixture of cobalt(II)(salen) and benzotrichloride (4) results in transformation of 4 successively into 1,1,2,2-tetrachloro-1,2-diphenylethane, 1,2-dichlorostilbene, diphenylacetylene, stilbene, and bibenzyl. The first three reactions are electrocatalyzed by the cobalt complex; the last two are direct reductions.
Electrolysis of trichloromethylated organic compounds under aerobic conditions catalyzed by the B12 model complex for ester and amide formation
Shimakoshi, Hisashi,Luo, Zhongli,Inaba, Takuya,Hisaeda, Yoshio
supporting information, p. 10173 - 10180 (2016/07/06)
The electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of the B12 model complex, heptamethyl cobyrinate perchlorate, in ethanol under aerobic conditions using an undivided cell equipped with a platinum mesh cathode and a zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. The corresponding esters were obtained when the electrolysis was carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for the ester formation. When the electrolysis was carried out under anaerobic conditions, partially dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms), were obtained instead of an ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that the corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides, such as substituted benzotrichlorides, are described. Furthermore, the formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by the B12 model complex in the presence of amines in acetonitrile is reported.
Oxygen-Controlled Catalysis by Vitamin B12-TiO2: Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation
Shimakoshi, Hisashi,Hisaeda, Yoshio
, p. 15439 - 15443 (2016/01/26)
An oxygen switch in catalysis of the cobalamin derivative (B12)-TiO2 hybrid catalyst for the dechlorination of trichlorinated organic compounds has been developed. The covalently bound B12 on the TiO2 surface transformed trichlorinated organic compounds into an ester and amide by UV light irradiation under mild conditions (in air at room temperature), while dichlorostilbenes (E and Z forms) were formed in nitrogen from benzotrichloride. A benzoyl chloride was formed as an intermediate of the ester and amide, which was detected by GC-MS. The substrate scope of the synthetic strategy is demonstrated with a range of various trichlorinated organic compounds. A photo-duet reaction utilizing the hole and conduction band electron of TiO2 in B12-TiO2 for the amide formation was also developed.
Chromium-carbyne complexes: Intermediates for organic synthesis
Bejot, Romain,He, Anyu,Falck, John R.,Mioskowski, Charles
, p. 1719 - 1722 (2008/02/13)
(Chemical Equation Presented) On the same route: Chromium-carbyne complexes are readily prepared by treatment of 1,1,1-trichloromethyl reagents with chromium(II) chloride. They serve as intermediates in the selective formation of a wide variety of products, such as alkynes, alkenes, β-hydroxy ketones, aldehydes, allylic alcohols, and allenes (see scheme, E = electrophile).
Tandem Pd/C-catalyzed reductive coupling and dehalogenation of benzylic halides
Joshi, Ashutosh V.,Baidossi, Mubeen,Taha, Nimer,Mukhopadhyay, Sudip,Sasson, Yoel
, p. 2715 - 2722 (2007/10/03)
High-yield reductive homocoupling of benzotrichloride and benzal chloride followed by consecutive reductive dechlorination to 1,2-dichlorostilbene and stilbene is effected in the presence of sodium formate as the reducing agent and Pd/C catalysts. Copyright Taylor & Francis, Inc.
Inter- and innermolecular reactions of chloro(phenyl)carbene
Rosenberg, Murray G.,Brinker, Udo H.
, p. 4819 - 4832 (2007/10/03)
Supramolecular photolyses of 3-chloro-3-phenyl-3H-diazirine (8) were performed within cyclodextrin (CyD) hosts to determine whether these toroidal inclusion compounds could alter the reactivity of the ensuing carbene reaction intermediate, chloro(phenyl)carbene (9). Remarkably, no intramolecular products stemming from carbene 9 could be detected. Instead, modified CyDs were formed via so-called innermolecular reactions. Hence, diazirine 8 was photolyzed in various conventional solvents to gauge the intermolecular reactivity of carbene 9. Relevant results were used to rationalize the CyD innermolecular reaction products.
Astonishing alkylation and unusual reduction reactions of anionic titanium(II) isopropoxide complexes: Evidence for SET processes in transition-metal oxidative additions
Eisch, John J.,Gitua, John N.
, p. 3091 - 3096 (2007/10/03)
A mixture of titanium(II) isopropoxide and lithium isopropoxide (1:2), generated in THF by the treatment of titanium(IV) isopropoxide with two equivalents of n-butyllithium, has been shown to be an unexpected alkylating agent as well as an unusual reducing agent for a wide variety of organic substrates. Since titanium(II) isopropoxide, which is free of any lithium isopropoxide, neither causes alkylation of any of the same substrates nor is such a powerful reductant, it is proposed that the lithium isopropoxide activates titanium(II) isopropoxide for such unusual reactions by the formation of the lithium salt coordination complex Li2Ti[OiPr]4. Illustrative of the unprecedented alkylations are the transformations, after hydrolysis, of various substituted benzonitriles to isopropyl-substituted phenyl ketones, of (dichloromethyl)benzene to, principally, 2-methyl-1-phenyl-1-propene and of (trichloromethyl)benzene to isopropyl phenyl ketone. By comparing the reducing actions of Li2Ti[OiPr]4 and Ti[OiPr]2 individually, it has been shown that, generally, the lithium salt is the more powerful reductant for epoxides, benzylic halides and conjugated olefins. From the reactions of Li2Ti[OiPr]4 with the benzonitriles, styrene, the isomeric stilbene oxides and cis-stilbene, cogent evidence is marshaled for the operation of SET processes, sensitive to steric hindrance, in such alkylations and reductions. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Organometallic chemistry sans organometallic reagents: Modulated electron-transfer reactions of sub valent early transition metal salts
Eisch, John J.,Shi, Xian,Alila, Joseph R.,Thiele, Sven
, p. 1175 - 1187 (2007/10/03)
The potential of low-valent, early transition-metal reagents as selective reductants in organic chemistry has been foreshadowed by intensive research on the ill-defined and heterogeneous subvalent titanium intermediates generated in the McMurry reaction and its numerous variants. As part of a long-term research effort to develop soluble, well-defined transition-metal reductants of modulated and selective activity toward organic substrates, the THF-soluble reductant, titanium dichloride, has been thoroughly examined, as well as the analogous ZrCl2 and HfCl2 reagents, all of which are readily obtainable by the alkylative reduction of the Group 4 tetrachloride by butyllithium in THF. Noteworthy is that such interactions of MCl4, with butyllithium in hydrocarbon media lead, in contrast, to M(III) or M(IV) halide hydrides. Analogous alkylative reductions in THF applied to VCl4, CrCl3, and MoCl5 have yielded reducing agents similar to those obtained from MCl4 but gradated in their reactivity. Such reductants have proved capable of coupling carbonyl derivatives, benzylic halides, acetylenes and certain olefins in a manner consistent with an oxidative addition involving a two-electron transfer (TET). Such a reaction pathway is consistent with the observed stereochemistry for pinacol formation from ketones and for the reductive dimerization of alkynes. In contrast to the reaction of CrCl3 with two equivalents of butyllithium, which leads to a CrCl intermediate, the interaction of CrCl3 in THF with four equivalents of butyllithium at -78°C yields a reagent of the empirical formulation, LiCrH4 · 2 LiCl · 2 THF, as supported by elemental and gasometric analysis of its protolysis. This hydridic reductant cleaves a wide gamut of o carbon-heteroatom bonds (C-X, C-O, C-S and C-N), towards which the CrCl reductant is unreactive. The type of cleavage and/or coupled products resulting from the action of "LiCrH4" on these substrates is best understood as arising from single-electron transfer (SET). In light of the aforementioned findings, the gradated reducing action noted among TiCl2, ZrCl2, HfCl2 and CrCl, as well as the contrasting reducing behavior between CrCl and LiCrH4, there is no doubt that future research with early transition metals will continue to yield novel reductants of modulated and site-selective reactivity. VCH Verlagsgesellschaft mbH,.
Reaction of Aromatic and Unsaturated Compounds with the Potassium Permanganate/HCI (HBr) Acetonitrile Reagent
Liu, Lilian Kao,Lin, Ching-Shan
, p. 61 - 66 (2007/10/03)
Addition of hydrochloric or hydrobromic acid to a solution of potassium permanganate in acetonitrile produced a homogeneous mixture, which is suitable for laboratory chlorination or bromination, respectively. Aromatic compounds more reactive than alkylbenzenes can be chlorinated or brominated without additional catalyst. Alkenes and alkynes give the corresponding vicinal dihaloalkanes and vinyl halides. All reactions complete within two hours under mild condition (25-60 °C) with excellent to moderate yields.
