38407-35-1Relevant academic research and scientific papers
Nickel-Catalyzed Selective Synthesis of α-Alkylated Ketones via Dehydrogenative Cross-Coupling of Primary and Secondary Alcohols
Bains, Amreen K,Biswas, Ayanangshu,Adhikari, Debashis
supporting information, p. 47 - 52 (2021/10/14)
Herein, we describe an isolable, air-stable, homogeneous, nickel catalyst that performs dehydrogenative cross-coupling reaction between secondary and primary alcohols to result α-alkylated ketone products selectively. The sequence of steps involve in this one-pot reaction is dehydrogenation of both alcohols, condensation between the ketone and the aldehyde, and hydrogenation of the in situ-generated α,β-unsaturated ketone. Preliminary mechanistic investigation hints a radical mechanism following borrowing hydrogen reaction. (Figure presented.).
Base-free transfer hydrogenation of aryl-ketones, alkyl-ketones and alkenones catalyzed by an IrIIICp* complex bearing a triazenide ligand functionalized with pyrazole
Medrano-Castillo, Layla J.,Collazo-Flores, Miguel á.,Camarena-Díaz, Juan P.,Correa-Ayala, Erick,Chávez, Daniel,Grotjahn, Douglas B.,Rheingold, Arnold L.,Miranda-Soto, Valentín,Parra-Hake, Miguel
, (2020/03/13)
An IrIIICp* complex (2) bearing a triazenide ligand functionalized with pyrazole was synthesized and fully characterized by spectroscopic methods and the structure confirmed by X-ray diffraction studies. The catalytic activity of 2 and the control complex 3, which lacks of pyrazole in its structure, was evaluated in the reduction of aryl-ketones, alkyl-ketones, α,β-unsaturated and γ,δ-unsaturated ketones. The catalytic system, using either 2 or 3, exhibited good to excellent selectivity when tested with ketones and alkenones at 90 °C in 2-propanol as hydrogen source under base-free conditions. Reactivity of 2 in 2-propanol and NaH gave a neutral metal hydride (4) while in the absence of base gave two major cationic hydrides species (5 and 6).
C?C Bond Formation of Benzyl Alcohols and Alkynes Using a Catalytic Amount of KOtBu: Unusual Regioselectivity through a Radical Mechanism
Kumar, Amit,Janes, Trevor,Chakraborty, Subrata,Daw, Prosenjit,von Wolff, Niklas,Carmieli, Raanan,Diskin-Posner, Yael,Milstein, David
supporting information, p. 3373 - 3377 (2019/02/14)
We report a C?C bond-forming reaction between benzyl alcohols and alkynes in the presence of a catalytic amount of KOtBu to form α-alkylated ketones in which the C=O group is located on the side derived from the alcohol. The reaction proceeds under thermal conditions (125 °C) and produces no waste, making the reaction highly atom efficient, environmentally benign, and sustainable. Based on our mechanistic investigations, we propose that the reaction proceeds through radical pathways.
Iron-Catalyzed Chemoselective Reduction of α,β-Unsaturated Ketones
Lator, Alexis,Gaillard, Sylvain,Poater, Albert,Renaud, Jean-Luc
supporting information, p. 5770 - 5774 (2018/03/26)
An iron-catalyzed chemo- and diastereoselective reduction of α,β-unsaturated ketones into the corresponding saturated ketones in mild reaction conditions is reported herein. DFT calculations and experimental work underline that transfer hydride reduction is a more facile process than hydrogenation, unveiling the fundamental role of the base.
Catalyst-free chemoselective conjugate addition and reduction of α,β-unsaturated carbonyl compounds: Via a controllable boration/protodeboronation cascade pathway
Huang, Xi,Hu, Junjie,Wu, Mengying,Wang, Jiayi,Peng, Yanqing,Song, Gonghua
, p. 255 - 260 (2018/01/12)
A novel, efficient transition-metal-free and controllable boration/protodeboronation strategy has been developed for the chemoselective conjugate addition and 1,4-reduction of α,β-unsaturated carbonyl compounds. Without any metal-catalyst or base, a series of β-boration products of α,β-unsaturated carbonyl compounds was easily obtained in moderate to excellent yields in a mixed solvent of ethanol and water. The presence of a catalytic amount of Cs2CO3 can effectively induce further protodeboronation reaction towards 1,4-reduction products at higher reaction temperature. Therefore, by slightly changing the reaction conditions, the boration or reduction products of α,β-unsaturated carbonyl compounds can be controllably obtained. Mechanistic studies revealed that Cs2CO3 played the key role in activating the protodeboronation step. This transition-metal-catalyst-free and product controllable method provides a useful and eco-friendly tool for the highly chemoselective preparation of the β-boration products and 1,4-reduction products of α,β-unsaturated carbonyl compounds.
Tandem addition β-lithiation - Alkylation sequence on α,β-unsaturated aldehydes
Nudelman,Garcia
, p. 1387 - 1394 (2007/10/03)
A tandem reaction between (E)-cinnamaldehyde, 1a, and phenyllithium affording β-substituted dihydrochalcones was recently reported. NMR spectroscopic studies on the reaction mixture, as well as isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that β-alkyl-substituted α,β-unsaturated aldehydes and aliphatic lithium reagents did not afford good yields of the tandem reaction products, while aromatic lithium reagents gave good results. The aggregation features of the aryllithium reagents and the extended charged delocalization effects are considered to promote β-selectivity. This approach provides a convenient route for the synthesis of a wide variety of β-alkyl-substituted dihydrochalcones.
