Article
Chemistry, Organic
Geraldo Duran-Camacho, J. Caleb Hethcox
Summary: A nickel-catalyzed cyanation reaction of (hetero)aryl halides using bis(trimethylaluminum)-1,4-diazabicyclo[2.2.2]octane (DABAL-Me3) as a soluble reductant has been developed. The reaction utilizes readily available and inexpensive precatalyst Ni(dppf)Cl2, substoichiometric amount of Zn(CN)2, and DABAL-Me3 as an alternative to insoluble reductants. The addition of catalytic tetrabutylammonium bromide (TBABr) aids in dissolving low levels of the cyanide salt for a completely homogeneous reaction mixture.
Article
Chemistry, Physical
Jonathan Heinrich Schacht, Shangze Wu, Sven Klare, Sebastian Hoethker, Niklas Schmickler, Andreas Gansaeuer
Summary: In this study, we demonstrate that polymethylhydrosiloxane (PMHS) can serve as a sustainable terminal reductant in the titanocene catalyzed hydrosilylation of epoxides. The resulting products are the anti-Markovnikov products of H2O-addition to alkenes. PMHS not only offers a more sustainable and cost-effective alternative to other silanes such as PhSiH3 and Ph(Me)SiH2, but also exhibits higher diastereoselectivity in epoxide reduction.
Article
Chemistry, Organic
Mengna Liu, Benqiang Cui, Chuntao Zhong, Yanhui Shi, Yanfeng Dang, Changsheng Cao
Summary: A palladium-catalyzed cyanation of aryl dimethylsulfonium salts using K-4[Fe-(CN)(6)]center dot 3H(2)O as the cyanating reagent was successfully developed. The reaction proceeded under base-free conditions and yielded aryl nitriles with up to 92% yields. The protocol also allowed direct transformation of aryl sulfides to aryl nitriles, and the reaction mechanism was investigated using density functional theory calculations.
Article
Chemistry, Organic
Serhii Krykun, Muriel Durandetti
Summary: A convenient and efficient method for the construction of aryl trifluoromethyl selenoethers from aryl iodides under mild conditions is reported. The electrochemical activation of stable and inexpensive NiBr(2)bipy complex replaces the use of labile Ni(COD)(2) catalyst. [NMe4][SeCF3] is employed as a stable source of SeCF3 fragment. The reaction tolerates a wide range of substrates, including drug-like molecules. Cyclic voltammetry studies provide insight into the reaction mechanism.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Vishal Kumar Rawat, Kosuke Higashida, Masaya Sawamura
Summary: In this study, nickel-catalyzed reductive homocoupling of aryl ethers was achieved using Mg(anthracene)(thf)(3) as a low-cost reductant. Density functional theory calculations provided insights into the specific efficiency of the diorganomagnesium-type two-electron reducing agent, with the dianionic anthracene-9,10-diyl ligand reducing the aryl ether substrates and facilitating the homocoupling reaction through electron transfer to the Ni-Mg bimetallic system. The calculations also showed the cooperative actions of Lewis acidic magnesium atoms and electron-rich nickel atoms in the C-O cleavage reactions.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Geyang Song, Qi Li, Ding-Zhan Nong, Jiameng Song, Gang Li, Chao Wang, Jianliang Xiao, Dong Xue
Summary: This paper describes a photochemical C-N coupling reaction of less reactive aryl chlorides with primary and secondary amides using a Ni catalyst without an external photocatalyst. The reaction proceeds under light irradiation (390-395 nm) with a soluble organic amine as the base, resulting in the successful synthesis of a wide range of N-aryl amides from (hetero)aryl chlorides. Mechanistic studies suggest that the amidation occurs via a Ni(I)-Ni(III) catalytic cycle.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Kathleen M. Morrison, Ryan T. McGuire, Michael J. Ferguson, Mark Stradiotto
Summary: This study reveals a new Ni-catalyst with unique ability to promote the cross-coupling of tertiary aliphatic alcohols with (hetero)aryl halides or phenol derivatives. Exploration of substrate scope and competition experiments shed light on the capabilities and reactivity preferences of this catalyst system.
Article
Chemistry, Multidisciplinary
Xiaomin Shu, De Zhong, Yanmei Lin, Xiao Qin, Haohua Huo
Summary: We report a general and modular approach for the direct enantioselective alpha-arylation of saturated azacycles and acyclic N-alkyl benzamides via nickel/photoredox dual catalysis. This method requires no oxidants or organometallic reagents, features broad substrate scope and high enantioselectivities, and is applicable to late-stage diversification of medicinally relevant complex molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Qinghua Ren, Dongtao Zhang, Gangchang Zhou
Summary: The mechanisms of nickel-catalyzed cyanation of aryl halides with 2-methyl-2-phenylmalononitrile through reductive-coupling reactions were investigated using density functional theory calculations. The rate-determining step in the overall catalytic cycle was found to be the oxidative addition step, consistent with experimental results.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Tristan Delcaillau, Adrian Woenckhaus-Alvarez, Bill Morandi
Summary: A nickel-catalyzed cyanation method using Zn(CN)(2) as the cyanide source has been developed for the functionalization of aryl thioethers, involving both C-S bond activation and C-C bond formation. The combination of ligand dcype and base KOAc is crucial for the efficiency of this transformation. The scalability, low catalyst and reagent loadings, and high functional group tolerance make this reaction useful for late-stage derivatization and polymer recycling in organic chemistry.
Article
Chemistry, Multidisciplinary
Ying Chen, Lanting Xu, Yongwen Jiang, Dawei Ma
Summary: The combination of copper salts and oxalic diamides enables the synthesis of α-(hetero)aryl nitriles via one-pot decarboxylation under mild conditions. The method demonstrates a broad substrate scope and compatibility with various functionalities and heteroaryls.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Guangzhu Wang, Chaoren Shen, Xinyi Ren, Kaiwu Dong
Summary: An intramolecular Heck cyclization catalyzed by Ni/(S,S)-BDPP was developed for the synthesis of oxindoles with good enantioselectivities. The use of an electrophilic cyanation reagent was found to address the deleterious effect of the coordinative cyanide ion in asymmetric alkene arylcyanation.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Koh Watanabe, Mitsutaka Takeda, Kazunori Nagao, Hirohisa Ohmiya
Summary: This article describes a catalytic reductive cross-coupling reaction between arylaldehydes and aryl electrophiles using a silylboronate as a terminal reductant. The protocol provides a new opportunity to access 1,1-diarylmethanol derivatives without the need for rare metals or highly basic organometallic reagents.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Minling Xu, Lijia Qian, Gang Zou
Summary: An air-tolerant reductive Heck reaction using nickel bromide catalyst and manganese reductant was developed, enabling the reaction of alkyl/aryl halides with α,β-unsaturated esters, nitriles, and amides in refluxing acetonitrile. Water played a dual role in the catalytic process, hydrolyzing enolate and/or C-tautomer intermediates to form conjugate adducts while suppressing catalysis at high concentration. The scope and limitations of this nickel-catalyzed manganese-mediated process were demonstrated through more than 40 examples, showing significant steric effects and good functional group compatibility, except for reduction-sensitive groups.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Organic
Valeriia Hutskalova, Farhan Bou Hamdan, Christof Sparr
Summary: An efficient methodology for the photoredox- and nickel-catalyzed aminocarbonylation of (hetero)aryl bromides was developed using readily available oxamic acids and a widely used organic photoredox catalyst. This transformation provides an attractive alternative to classical amidation procedures, with mild reaction conditions.
