The challenging nickel-catalyzed mono-α-arylation of acetone with aryl chlorides, pivalates, and carbamates has been achieved for the first time. A nickel/Josiphos-based catalytic system is shown to feature unique catalytic behavior, allowing the highly selective formation of the desired mono-α-arylated acetone. The developed methodology was applied to a variety of (hetero)aryl chlorides including biologically relevant derivatives. The methodology has been extended to the unprecedented coupling of acetone with phenol derivatives. Mechanistic studies allowed the isolation and characterization of key Ni and Ni catalytic intermediates. The Josiphos ligand is shown to play a key role in the stabilization of Ni intermediates to allow a Ni /Ni catalytic pathway. Mechanistic understanding was then leveraged to improve the protocol using an air-stable Ni pre-catalyst.
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http://dx.doi.org/10.1002/anie.202006826 | DOI Listing |
J Am Chem Soc
September 2024
Department of Chemistry, School of Natural Sciences, Shiv Nadar IoE Deemed to be University, Delhi-NCR Dadri, Chithera, Gautam Buddha Nagar, Uttar Pradesh 201314, India.
Electro-photochemical organic synthesis is a rapidly growing field. Recently, technological advancement has contributed significantly to improve electro- and photolytic organic transformations in terms of energy efficiency and productivity. Herein, we have introduced alternating electrode electrolysis|alternate electrode electrolysis (AEE), a new technique in electrosynthesis which in combination with blue LED demonstrated an interesting three-component reaction with aryl diazoesters, 1,4-quinones, and acetone to synthesize ketal-functionalized 1,4-quinones.
View Article and Find Full Text PDFOrganometallics
August 2024
Grupo de Química Organometálica, Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Murcia E-30071, Spain.
The polynuclear complex [{μ-1,4,,″-CH{C(H)=N(Bu)}-2,5}{Pd(μ-OAc)}] () reacts with tbbpy (4,4'-di--butyl-2,2'-bipyridine) and TlOTf to form the dinuclear complex [{μ-1,4,,″-CH{C(H)=N(Bu)}-2,5}{Pd(tbbpy)}] (). The hydrolysis of with acetic acid in a 5:1 acetone/water mixture, in the presence of two equivalents of tbbpy and excess NaX (X = Br, I), yields the dipalladated terephthalaldehyde complexes [CH{PdX(tbbpy)}-1,4-(CHO)-2,5] [X = Br (), X = I ()], which are the first fully characterized complexes of this type. The reaction of with CO results in the insertion of CO into both aryl-Pd bonds, forming [CH{C(O){PdX(tbbpy)}}-1,4-(CHO)-2,5] [X = Br (), X = I ()], which are the first examples of complexes with CO inserted into two separate aryl-metal bonds involving the same ligand.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462 066, India.
Herein, we disclose the first report on gold-catalyzed C(sp)-CN cross-coupling reaction by employing a ligand-enabled Au(I)/Au(III) redox catalysis. This transformation utilizes acetone cyanohydrin as a nucleophilic cyanide source to convert simple aryl and alkenyl iodides into the corresponding nitriles. Combined experimental and computational studies highlighted the crucial role of cationic silver salts in activating the stable (P,N)-AuCN complex towards the oxidative addition of aryl iodides to subsequently generate key aryl-Au(III) cyanide complexes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Chair of Inorganic Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
Palladium-catalyzed coupling reactions of small nucleophiles are of great interest, but challenging due to difficulties in selectivity control. Herein, we report the development of a new platform of P,N-ligands consisting of ylide-functionalized phosphines with aminophosphonium groups (NYPhos) to address this challenge. These phosphine ligands are easily accessible in a wide structural diversity with highly modular electronic and steric properties.
View Article and Find Full Text PDFOrg Biomol Chem
July 2024
Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
We described the influence of steric hindrance on the 1,4- 1,6-Michael addition reaction on 2-(3,3-bis(methylthio)-1-arylallylidene)malononitriles. An efficient and direct synthesis of trisubstituted furans was achieved through the reaction of 2-(3,3-bis(methylthio)-1-arylallylidene)malononitriles and acetone under mild conditions in good to moderate yield by the 1,4-Michael addition. Further exploration of the reaction with a sterically hindered aryl group containing 2-(3,3-bis(methylthio)-1-arylallylidene)malononitriles afforded biaryls by an generated nucleophile through the 1,6-Michael addition.
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