2653-89-6Relevant academic research and scientific papers
Synthesis, solid-state structures, solution behaviour and catalysis studies of nickel complexes of bis(benzimidazolin-2-ylidene)pyridine pincer ligands
Magee, Karen D.M.,Travers, Guy,Skelton, Brian W.,Massi, Massimilliano,Payne, Alan D.,Brown, David H.
, p. 823 - 833 (2012)
N-Heterocyclic carbenenickel complexes with five- and four-coordinate geometries [(CNC)NiBr2] and [(CNC)NiBr]X (X=PF6 or BPh4) have been prepared with the pincer ligands 2,6-bis(N- octylbenzimidazolin-2-ylidene)pyridine and 2,6-bis(N-butyl-5,6- dimethoxybenzimidazolin-2-ylidene)pyridine. The addition of the n-octyl substituent significantly extends the solubility of the complexes and has allowed UV-vis solution studies of the complexes in dichloromethane and methanol. The four- and five-coordinate species exist in equilibrium in solution and this equilibrium has been explored by UV-vis studies. The complexes have also been characterized by NMR studies, and single crystal X-ray diffraction studies have been performed on [(CNC)NiBr2] (where CNC=2,6-bis(N-octylbenzimidazolin-2-ylidene)pyridine) and [(CNC)NiBr]BPh 4 (where CNC=2,6-bis(N-butyl-5,6-dimethoxybenzimidazolin-2-ylidene) pyridine).
Palladium-catalyzed anti-Markovnikov oxidative acetalization of activated olefins with iron(iii) sulphate as the reoxidant
Fernandes, Rodney A.,Kumar, Praveen,Yadav, Sandhya S.
, p. 427 - 443 (2022/01/20)
This paper discloses the efficient palladium-catalyzed anti-Markovnikov oxidative acetalization of activated terminal olefins with iron(iii) sulfate as the reoxidant. This methodology requires mild reaction conditions and shows high regioselectivity toward anti-Markovnikov products and compatibility with a wide range of functional groups. Iron(iii) sulphate was the sole reoxidant used in this method. Various olefins like vinylarenes, aryl-allylethers, aryl or benzyl acrylates and homoallylic alcohols all reacted well providing anti-Markovnikov acetals, some of which represent orthogonally functionalized 1,3- and 1,4-dioxygenated compounds.
Application of Bifunctional 2-Amino-1,4-naphthoquinones in Visible-Light-Promoted Photocatalyst-Free Alkene Perfluoroalkyl-Alkenylation
Tang, Lin,Yang, Fang,Yang, Zhen,Chen, Hanfei,Cheng, Hao,Zhang, Shuaifei,Zhou, Qiuju,Rao, Weihao
supporting information, p. 519 - 524 (2021/02/03)
A simple and practical photochemical strategy for intermolecular perfluoroalkyl-alkenylation of alkenes with 2-amino-1,4-naphthoquinones and perfluoroalkyl iodides has been demonstrated under visible-light irradiation. Mechanistic studies reveal that easily available 2-amino-1,4-naphthoquinone substrates can serve as efficient photosensitizers to activate perfluoroalkyl iodides through a photoredox process. Therefore, the developed radical relay reaction proceeds smoothly without additional transition metals and photocatalysts.
Iron(II) and Copper(I) Control the Total Regioselectivity in the Hydrobromination of Alkenes
Cruz, Daniel A.,Sinka, Victoria,De Armas, Pedro,Steingruber, Hugo Sebastian,Fernández, Israel,Martín, Víctor S.,Miranda, Pedro O.,Padrón, Juan I.
supporting information, p. 6105 - 6109 (2021/08/18)
A new method that allows the complete control of the regioselectivity of the hydrobromination reaction of alkenes is described. Herein, we report a radical procedure with TMSBr and oxygen as common reagents, where the formation of the anti-Markovnikov product occurs in the presence of parts per million amounts of the Cu(I) species and the formation of the Markovnikov product occurs in the presence of 30 mol % iron(II) bromide. Density functional theory calculations combined with Fukui's radical susceptibilities support the obtained results.
Nickel-catalyzed removal of alkene protecting group of phenols, alcohols via chain walking process
Meng, Chenkai,Niu, Haolin,Ning, Juehan,Wu, Wengang,Yi, Jun
supporting information, (2020/02/04)
An efficient nickel-catalyzed removal of alkene protection group under mild condition with high functional group tolerance through chain walking process has been established. Not only phenolic ethers, but also alcoholic ethers can be tolerated with the retention of stereocenter adjacent to hydroxyl group. The new reaction brings the homoallyl group into a start of new type of protecting group.
Linear Hydroaminoalkylation Products from Alkyl-Substituted Alkenes
Warsitz, Michael,Doye, Sven
supporting information, p. 15121 - 15125 (2020/10/23)
The regioselective conversion of alkyl-substituted alkenes into linear hydroaminoalkylation products represents a strongly desirable synthetic transformation. In particular, such conversions of N-methylamine derivatives are of great scientific interest, because they would give direct access to important amines with unbranched alkyl chains. Herein, we present a new one-pot procedure that includes an initial alkene hydroaminoalkylation with an α-silylated amine substrate and a subsequent protodesilylation reaction that delivers linear hydroaminoalkylation products with high selectivity from simple alkyl-substituted alkenes. For that purpose, new titanium catalysts have been developed, which are able to activate the α-C?H bond of more challenging α-silylated amine substrates. In addition, a direct relationship between the ligand structure of the new catalysts and the obtained regioselectivity is described.
Organophotoredox/palladium dual catalytic decarboxylative Csp3-Csp3coupling of carboxylic acids and π-electrophiles
Cartwright, Kaitie C.,Tunge, Jon A.
, p. 8167 - 8175 (2020/09/09)
A dual catalytic decarboxylative allylation and benzylation method for the construction of new C(sp3)-C(sp3) bonds between readily available carboxylic acids and functionally diverse carbonate electrophiles has been developed. The new process is mild, operationally simple, and has greatly improved upon the efficiency and generality of previous methodology. In addition, new insights into the reaction mechanism have been realized and provide further understanding of the harnessed reactivity.
Reductive C-O, C-N, and C-S Cleavage by a Zirconium Catalyzed Hydrometalation/β-Elimination Approach
Matt, Christof,K?lblin, Frederic,Streuff, Jan
, p. 6983 - 6988 (2019/09/09)
A zirconium catalyzed reductive cleavage of Csp3 and Csp2 carbon-heteroatom bonds is reported that makes use of a tethered alkene functionality as a traceless directing group. The reaction is successfully demonstrated on C-O, C-N, and C-S bonds and proposed to proceed via a hydrozirconation/β-heteroatom elimination sequence of an in situ formed zirconium hydride catalyst. The positional isomerization of the catalyst further enables the cleavage of homoallylic ethers and the removal of terminal allyl and propargyl groups.
Tuning Regioselectivity of Wacker Oxidation in One Catalytic System: Small Change Makes Big Step
Hu, Kang-Fei,Ning, Xiao-Shan,Qu, Jian-Ping,Kang, Yan-Biao
, p. 11327 - 11332 (2018/09/06)
A regioselectivity switchable aerobic Wacker-Tsuji oxidation has been developed using catalytic tert-butyl nitrite as a simple organic redox cocatalyst. By solely switching the solvent, either substituted aldehydes or ketones could be prepared under mild
Intermolecular Palladium-Catalyzed Oxidative Fluorocarbonylation of Unactivated Alkenes: Efficient Access to β-Fluorocarboxylic Esters
Qi, Xiaoxu,Yu, Feng,Chen, Pinhong,Liu, Guosheng
supporting information, p. 12692 - 12696 (2017/10/06)
A novel palladium-catalyzed intermolecular oxidative fluorocarbonylation of alkenes has been developed, in which employment of a cooperative process with electrophilic ArIF2-meidated alkenes activation and palladium-catalyzed carbonylation is c
