19935-78-5Relevant academic research and scientific papers
Nickel-Catalyzed Multicomponent Coupling: Synthesis of α-Chiral Ketones by Reductive Hydrocarbonylation of Alkenes
Chen, Jian,Zhu, Shaolin
supporting information, p. 14089 - 14096 (2021/09/13)
A nickel-catalyzed, multicomponent regio- and enantioselective coupling via sequential hydroformylation and carbonylation from readily available starting materials has been developed. This modular multicomponent hydrofunctionalization strategy enables the straightforward reductive hydrocarbonylation of a broad range of unactivated alkenes to produce a wide variety of unsymmetrical dialkyl ketones bearing a functionalized α-stereocenter, including enantioenriched chiral α-aryl ketones and α-amino ketones. It uses chiral bisoxazoline as a ligand, silane as a reductant, chloroformate as a safe CO source, and a racemic secondary benzyl chloride or an N-hydroxyphthalimide (NHP) ester of a protected α-amino acid as the alkylation reagent. The benign nature of this process renders this method suitable for late-stage functionalization of complex molecules.
Metal-free regioselective hydrochlorination of unactivated alkenes via a combined acid catalytic system
Liang, Shengzong,Hammond, Gerald B.,Xu, Bo
supporting information, p. 680 - 684 (2018/02/14)
A combined acid HCl/DMPU-acetic acid catalytic system was used in the hydrochlorination of a wide range of unactivated alkenes. This hydrochlorination strategy is remarkably greener than previous reported methods in terms of high atom efficiency, no toxic waste generated and metal-free process. The higher efficiency, compared with other commercially available HCl reagents, was augmented by the good regioselectivity and functionality tolerance found. A stepwise mechanism for this hydrochlorination process was proposed based on kinetic studies.
Nickel-Catalyzed Reductive Cross-Coupling of Benzyl Halides with Aryl Halides
Zhang, Qingchen,Wang, Xuan,Qian, Qun,Gong, Hegui
supporting information, p. 2829 - 2836 (2016/08/31)
Systematic studies of the coupling of benzylic with aryl halides are presented. The optimized reaction conditions for electron-deficient aryl halides cannot be applied to the electron-rich or neutral counterparts, and vice versa. The excellent functional group tolerance and broad substrate scope may enable the current work to be useful for the construction of diaryl methane products.
Nickel-catalyzed asymmetric reductive cross-coupling between vinyl and benzyl electrophiles
Cherney, Alan H.,Reisman, Sarah E.
supporting information, p. 14365 - 14368 (2014/12/11)
A Ni-catalyzed asymmetric reductive cross-coupling between vinyl bromides and benzyl chlorides has been developed. This method provides direct access to enantioenriched products bearing aryl-substituted tertiary allylic stereogenic centers from simple, stable starting materials. A broad substrate scope is achieved under mild reaction conditions that preclude the pregeneration of organometallic reagents and the regioselectivity issues commonly associated with asymmetric allylic arylation.
Catalytic asymmetric reductive acyl cross-coupling: Synthesis of enantioenriched acyclic α,α-disubstituted ketones
Cherney, Alan H.,Kadunce, Nathaniel T.,Reisman, Sarah E.
supporting information, p. 7442 - 7445 (2013/06/27)
The first enantioselective Ni-catalyzed reductive acyl cross-coupling has been developed. Treatment of acid chlorides and racemic secondary benzyl chlorides with a NiII/bis(oxazoline) catalyst in the presence of Mn0 as a stoichiometric reductant generates acyclic α,α-disubstituted ketones in good yields and high enantioselectivity without requiring stoichiometric chiral auxiliaries or pregeneration of organometallic reagents. The mild, base-free reaction conditions are tolerant of a variety of functional groups on both coupling partners.
Nucleophilic Substitution Reaction of 1-Phenylethyl Chlorides in Methanol
Lee, Ikchoon,Lee, Won Heui,Lee, Hai Whang,Bentley, T. W.
, p. 141 - 146 (2007/10/02)
Nucleophilic substitution reactions of 1-(Y-phenyl)ethyl chlorides with X-anilines have been investigated in methanol at 65.0 deg C.An isokinetic point is obtained at ?Y+ = ca. -0.23 with ρX = 0; the sign of ρX changes at this point from positive for the relatively strong electron donating Y substituents to negative for the more electron withdrawing Y substituents. The magnitude of the cross-interaction constant, ρXY, between the substituents X and Y is unusually large with the relatively small magnitude of ρXo resulting in an observable isokinetic point at .These results are interpreted in terms of a transition state (TS) structure in which nearly complete bond formation between the nucleophile and cation formed in an ion-pair preequilibrium is coupled with a TS imbalance phenomenon.The results of kinetic isotope effect studies involving deuteriated anilines and methanol are also in line with this mechanism.
Process for the preparation of substituted vinylbenzyl chloride
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, (2008/06/13)
An improved continous single step vapor phase process for the preparation of substituted vinylbenzyl chloride from substituted ethyltoluene is disclosed. In this process a substituted ethyltoluene is reacted with a halogen gas in the vapor phase, at elevated temperatures via a continuous feed process. Furthermore, this process achieves halogenation followed by dehydrohalogenation in a single pass through the reactor. There is also obtained a very high total selectivity to vinylbenzyl chloride and its precursors via this continuous process.
