180286-97-9Relevant academic research and scientific papers
The copper-catalysed Suzuki-Miyaura coupling of alkylboron reagents: disproportionation of anionic (alkyl)(alkoxy)borates to anionic dialkylborates prior to transmetalation
Basnet, Prakash,Thapa, Surendra,Dickie, Diane A.,Giri, Ramesh
, p. 11072 - 11075 (2016)
We report the first example of CuI-catalysed coupling of alkylboron reagents with aryl and heteroaryl iodides that affords products in good to excellent yields. Preliminary mechanistic studies with alkylborates indicate that the anionic (alkoxy)(alkyl)borates, generated from alkyllithium and alkoxyboron reagents, undergo disproportionation to anionic dialkylborates and that both anionic alkylborates are active for transmetalation to a CuI-catalyst. Results from a radical clock experiment and the Hammett plot imply that the reaction likely proceeds via a non-radical pathway.
Direct Synthesis of Ketones from Methyl Esters by Nickel-Catalyzed Suzuki–Miyaura Coupling
Daneshfar, Omid,Hong, Xin,Houk, Kendall N.,Newman, Stephen G.,Xie, Pei-Pei,Zheng, Yan-Long
supporting information, p. 13476 - 13483 (2021/05/10)
The direct conversion of alkyl esters to ketones has been hindered by the sluggish reactivity of the starting materials and the susceptibility of the product towards subsequent nucleophilic attack. We have now achieved a cross-coupling approach to this transformation using nickel, a bulky N-heterocyclic carbene ligand, and alkyl organoboron coupling partners. 65 alkyl ketones bearing diverse functional groups and heterocyclic scaffolds have been synthesized with this method. Catalyst-controlled chemoselectivity is observed for C(acyl)?O bond activation of multi-functional substrates bearing other bonds prone to cleavage by Ni, including aryl ether, aryl fluoride, and N-Ph amide functional groups. Density functional theory calculations provide mechanistic support for a Ni0/NiII catalytic cycle and demonstrate how stabilizing non-covalent interactions between the bulky catalyst and substrate are critical for the reaction's success.
Palladium-Catalyzed Carbonylative Cross-Coupling of Difluoroalkyl Halides with Alkylboranes under 1 atm of CO
Zhang, Xingang,Zhao, Hai-Yang,Zhou, Minqi
supporting information, p. 9106 - 9111 (2021/12/06)
A palladium catalyzed carbonylative cross-coupling of difluoroalkyl halides with alkyl-9-BBN under 1 atm of CO has been developed. The reaction shows broad substrate scope and high functional group tolerance, even toward complex pharmaceuticals, providing
Ligand-Controlled Chemoselective C(acyl)-O Bond vs C(aryl)-C Bond Activation of Aromatic Esters in Nickel Catalyzed C(sp2)-C(sp3) Cross-Couplings
Chatupheeraphat, Adisak,Liao, Hsuan-Hung,Srimontree, Watchara,Guo, Lin,Minenkov, Yury,Poater, Albert,Cavallo, Luigi,Rueping, Magnus
supporting information, p. 3724 - 3735 (2018/03/21)
A ligand-controlled and site-selective nickel catalyzed Suzuki-Miyaura cross-coupling reaction with aromatic esters and alkyl organoboron reagents as coupling partners was developed. This methodology provides a facile route for C(sp2)-C(sp3) bond formation in a straightforward fashion by successful suppression of the undesired β-hydride elimination process. By simply switching the phosphorus ligand, the ester substrates are converted into the alkylated arenes and ketone products, respectively. The utility of this newly developed protocol was demonstrated by its wide substrate scope, broad functional group tolerance and application in the synthesis of key intermediates for the synthesis of bioactive compounds. DFT studies on the oxidative addition step helped rationalizing this intriguing reaction chemoselectivity: whereas nickel complexes with bidentate ligands favor the C(aryl)-C bond cleavage in the oxidative addition step leading to the alkylated product via a decarbonylative process, nickel complexes with monodentate phosphorus ligands favor activation of the C(acyl)-O bond, which later generates the ketone product.
Switchable Selectivity in the Pd-Catalyzed Alkylative Cross-Coupling of Esters
Masson-Makdissi, Jeanne,Vandavasi, Jaya Kishore,Newman, Stephen G.
supporting information, p. 4094 - 4098 (2018/07/15)
The Pd-catalyzed cross-coupling of phenyl esters and alkyl boranes is disclosed. Two reaction modes are rendered accessible in a selective fashion by interchange of the catalyst. With a Pd-NHC system, alkyl ketones can be prepared in good yields via a Suzuki-Miyaura reaction proceeding by activation of the C(acyl)-O bond. Use of a Pd-dcype catalyst enables alkylated arenes to be synthesized by a modified pathway with extrusion of CO. Applications of this divergent coupling strategy and the origin of the switchable selectivity are discussed.
Nickel-Catalyzed Alkoxy–Alkyl Interconversion with Alkylborane Reagents through C?O Bond Activation of Aryl and Enol Ethers
Guo, Lin,Liu, Xiangqian,Baumann, Christoph,Rueping, Magnus
supporting information, p. 15415 - 15419 (2016/12/03)
A nickel-catalyzed alkylation of polycyclic aromatic methyl ethers as well as methyl enol ethers with B-alkyl 9-BBN and trialkylborane reagents that involves the cleavage of stable C(sp2)?OMe bonds is described. The transformation has a wide substrate scope and good chemoselectivity profile while proceeding under mild reaction conditions; it provides a versatile way to form C(sp2)?C(sp3) bonds that does not suffer from β-hydride elimination. Furthermore, a selective and sequential alkylation process by cleavage of inert C?O bonds is presented to demonstrate the advantage of this method.
Enantioselective Suzuki cross-couplings of unactivated 1-fluoro-1-haloalkanes: Synthesis of chiral β-, γ-, δ-, and ε-fluoroalkanes
Jiang, Xiaojian,Gandelman, Mark
supporting information, p. 2542 - 2547 (2015/03/04)
The incorporation of fluorine atom into a stereogenic center is a highly challenging transformation with current methodologies offering access mainly to chiral α- and β-fluoroalkanes. In this article, the development of a novel general approach to constru
Efficient synthesis of secondary alkyl fluorides via suzuki cross-coupling reaction of 1-halo-1-fluoroalkanes
Jiang, Xiaojian,Sakthivel, Sekarpandi,Kulbitski, Kseniya,Nisnevich, Gennady,Gandelman, Mark
supporting information, p. 9548 - 9551 (2014/07/22)
Organofluorine compounds have found extensive applications in various areas of science. Consequently, the development of new efficient and selective methods for their synthesis is an important goal in organic chemistry. Here, we present the first Suzuki c
Preparation of imides via the palladium-catalyzed coupling reaction of organoborons with methyl N -[methoxy(methylthio)methylene]carbamate as a one-carbon elongation reaction
Tomizawa, Takuhei,Orimoto, Kohei,Niwa, Takashi,Nakada, Masahisa
supporting information, p. 6294 - 6297 (2013/02/23)
The preparation of imides via the palladium-catalyzed coupling reaction as a one-carbon elongation reaction is described. The palladium-catalyzed coupling reaction of aryl-, alkyl-, and alkenylborons with N-[methoxy(methylthio) methylene]carbamate in the presence of Cu(I) thiophene-2-carboxylate (CuTC) affords imino ethers that are converted to the corresponding imides by acidic hydrolysis in high yield. The imino ethers are also useful for preparing the corresponding ester without using carbon monoxide.
Catalytic asymmetric γ-alkylation of carbonyl compounds via stereoconvergent suzuki cross-couplings
Zultanski, Susan L.,Fu, Gregory C.
supporting information; experimental part, p. 15362 - 15364 (2011/11/11)
With the aid of a chiral nickel catalyst, enantioselective γ- (and I-) alkylations of carbonyl compounds can be achieved through the coupling of γ-haloamides with alkylboranes. In addition to primary alkyl nucleophiles, for the first time for an asymmetric cross-coupling of an unactivated alkyl electrophile, an arylmetal, a boronate ester, and a secondary (cyclopropyl) alkylmetal compound are shown to couple with significant enantioselectivity. A mechanistic study indicates that cleavage of the carbon-halogen bond of the electrophile is irreversible under the conditions for asymmetric carbon-carbon bond formation.
