347885-68-1Relevant academic research and scientific papers
A mild exchange reaction of xanthates with bromine
Barbier, Francis,Pautrat, Fran?ois,Quiclet-Sire, Béatrice,Zard, Samir Z.
, p. 811 - 813 (2002)
Secondary S-alkyl-O-ethyl (or O-neopentyl) xanthates can be converted into the corresponding bromides by heating with ethyl 2-bromo-2-methylpropionate and cumyl peroxide in refluxing chlorobenzene; this transformation can be coupled to a xanthate transfer radical addition to an olefin.
Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
supporting information, p. 14806 - 14813 (2021/09/18)
We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
Reductive Radical Conjugate Addition of Alkyl Electrophiles Catalyzed by a Cobalt/Iridium Photoredox System
Escobar, Randolph A.,Johannes, Jeffrey W.
supporting information, p. 6046 - 6051 (2021/08/03)
Alkyl and aryl halides have been studied extensively as radical precursors; however, mild and less toxic conditions for the activation of alkyl bromides toward alkyl radicals are still desirable. Reported here is a reductive radical conjugate addition tha
Ni-Catalyzed Formal Cross-Electrophile Coupling of Alcohols with Aryl Halides
Lin, Quan,Ma, Guobin,Gong, Hegui
, p. 14102 - 14109 (2021/11/20)
Direct coupling of unactivated alcohols remains a challenge in current synthetic chemistry. We herein demonstrate a strategy building upon in situ halogenation/reductive coupling of alcohols with aryl halides to forge Csp2-Csp3 bonds. The combination of 2-chloro-3-ethylbenzo[d]oxazol-3-ium salt (CEBO) and TBAB as the mild bromination reagents enables rapid transformation of a wide range of alcohols to their bromide counterparts within one to 5 min in CH3CN and DMF, which is compatible with the Ni-catalyzed cross-electrophile coupling conditions in the presence of a chemical reductant. The present method is suitable for arylation of a myriad of structurally complex alcohols with no need for prepreparation of alkyl halides. More importantly, the mild and kinetically rapid bromination process has shown good selectivity in the bromination/arylation of symmetric diols and less sterically hindered hydroxyl groups in polyols, thus offering promise for selective functionalization of diols and polyols without laborious protecting/deprotecting operations. The practicality of this work is also evident in the arylation of a number of carbohydrates, drug compounds, and naturally occurring alcohols.
Method for hydrogenolysis of halides
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Paragraph 0106-0109, (2021/01/11)
The invention discloses a method for hydrogenolysis of halides. The invention discloses a preparation method of a compound represented by a formula I. The preparation method comprises the following step: in a polar aprotic solvent, zinc, H2O and a compound represented by a formula II are subjected to a reaction as shown in the specification, wherein X is halogen; Y is -CHRR or R; hydrogenin H2O exists in the form of natural abundance or non-natural abundance. According to the preparation method, halide hydrogenolysis can be simply, conveniently and efficiently achieved through a simple and mild reaction system, and good functional group compatibility and substrate universality are achieved.
Preparation method of alkyl nitrile compound
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Paragraph 0177-0179, (2020/05/14)
The invention discloses a preparation method of an alkyl nitrile compound shown as formula I. The preparation method comprises the following step: in a solvent, in the presence of an additive and a catalyst, Zn (CN) 2 and an alkyl halide shown as formula II are subjected to a coupling reaction as shown in the specification to obtain the alkyl nitrile compound as shown in the formula I, wherein theadditive comprises an alkali, the catalyst comprises a nickel compound and a phosphine ligand; the nickel compound is one or more of zero-valent nickel, monovalent nickel salt and divalent nickel salt; when the nickel compound contains zero-valent nickel or divalent nickel salt, the catalyst further comprises a reducing agent. According to the preparation method disclosed by the invention, cyanation of an alkyl halide can be simply, conveniently and efficiently realized by using a cheap catalytic system, and the preparation method also has good functional group compatibility and substrate universality.
Nickel-Catalyzed Cyanation of Unactivated Alkyl Sulfonates with Zn(CN)2
Xia, Aiyou,Lv, Peizhuo,Xie, Xin,Liu, Yuanhong
supporting information, p. 7842 - 7847 (2020/11/02)
Cyanation of unactivated primary and secondary alkyl mesylates with Zn(CN)2 catalyzed by nickel has been developed. The reaction provides an efficient route for the synthesis of alkyl nitriles with wide substrate scope, good functional group tolerance, and compatibility with heterocyclic compounds. Mechanistic studies indicate that alkyl iodide generated in situ serves as the reactive intermediate and the gradual release of alkyl iodide is crucial for the success of the reaction.
Decarboxylative Bromination of Sterically Hindered Carboxylic Acids with Hypervalent Iodine(III) Reagents
Kanazawa, Junichiro,Koyamada, Kenta,Miyamoto, Kazunori,Uchiyama, Masanobu,Watanabe, Ayumi
supporting information, p. 1328 - 1334 (2020/08/14)
Sterically hindered three-dimensional (3D) alkyl halides are promising precursors for various reactions; however, they are difficult to synthesize via conventional reactions. We present an efficient and practical method for decarboxylative bromination of sterically hindered 3D aliphatic carboxylic acids using commercially available (diacetoxyiodo)benzene and potassium bromide, one of the most stable and cheapest bromine sources in nature. The present method features a metal-free/Br2-free system, mild reaction conditions, one-pot operation under air at room temperature, wide functional group compatibility, and gram-scale synthetic capability. This highly efficient reaction cleanly converts a broad range of carboxylic acids, the most inexpensive and readily available sources of highly strained/naturally occurring/drug-related scaffolds, into the corresponding alkyl bromides in good to high yields.
Iron-catalyzed protodehalogenation of alkyl and aryl halides using hydrosilanes
Pilli, Ramadevi,Balakrishnan, Venkadesh,Chandrasekaran, Revathi,Rasappan, Ramesh
supporting information, p. 1749 - 1753 (2019/02/20)
A simple and efficient iron-catalyzed protodehalogenation of alkyl and aryl halides using phenylhydrosilane is disclosed. The reaction utilizes FeCl3 without the requirement of ligands. Unactivated alkyl and aryl halides were successfully reduced in good yields; sterically hindered tertiary halides were also reduced including the less reactive chlorides. The scalability of this methodology was demonstrated by a gram-scale synthesis with a catalyst loading as low as 0.5 mol%. Notably, disproportionation of phenylsilane leads to diphenylsilane that further reduces the halides. Preliminary mechanistic studies revealed a non-radical pathway and the source of hydrogen is PhSiH3via deuterium labeling studies. Our methodology represents simplicity and provides a good alternative to typical tin, aluminum and boron hydride reagents.
Silver-Catalyzed Decarboxylative Bromination of Aliphatic Carboxylic Acids
Tan, Xinqiang,Song, Tao,Wang, Zhentao,Chen, He,Cui, Lei,Li, Chaozhong
supporting information, p. 1634 - 1637 (2017/04/11)
The silver-catalyzed Hunsdiecker bromination of aliphatic carboxylic acids is described. With Ag(Phen)2OTf as the catalyst and dibromoisocyanuric acid as the brominating agent, various aliphatic carboxylic acids underwent decarboxylative bromination to provide the corresponding alkyl bromides under mild conditions. This method not only is efficient and general but also enjoys wide functional group compatibility. An oxidative radical mechanism involving Ag(II) intermediates is proposed.
