Nickel‐Catalyzed Selective Synthesis of α‐Alkylated Ketones via Dehydrogenative Cross‐Coupling of Primary and Secondary Alcohols
作者:Amreen K Bains、Ayanangshu Biswas、Debashis Adhikari
DOI:10.1002/adsc.202101077
日期:2022.1.4
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
Tandem Addition β-Lithiation−Alkylation Sequence on α,β-Unsaturated Aldehydes
作者:Norma Sbarbati Nudelman、Graciela V. García
DOI:10.1021/jo005698d
日期:2001.2.1
isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that beta-alkyl-substituted alpha,beta-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
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.
C−C Bond Formation of Benzyl Alcohols and Alkynes Using a Catalytic Amount of KO<sup>t</sup>
Bu: Unusual Regioselectivity through a Radical Mechanism
作者:Amit Kumar、Trevor Janes、Subrata Chakraborty、Prosenjit Daw、Niklas von Wolff、Raanan Carmieli、Yael Diskin-Posner、David Milstein
DOI:10.1002/anie.201812687
日期:2019.3.11
We report a C−Cbond‐forming reaction between benzylalcohols and alkynes in the presence of a catalyticamount 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
Base-free transfer hydrogenation of aryl-ketones, alkyl-ketones and alkenones catalyzed by an IrIIICp* complex bearing a triazenide ligand functionalized with pyrazole
作者:Layla J. Medrano-Castillo、Miguel Á. Collazo-Flores、Juan P. Camarena-Díaz、Erick Correa-Ayala、Daniel Chávez、Douglas B. Grotjahn、Arnold L. Rheingold、Valentín Miranda-Soto、Miguel Parra-Hake
DOI:10.1016/j.ica.2020.119551
日期:2020.7
An (IrCp)-Cp-III* 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, alpha,beta-unsaturated and gamma, delta-unsaturated ketones. The catalytic system, using either 2 or 3, exhibited good to excellent selectivity when tested with ketones and alkenones at 90 degrees 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).