Ruthenium-NHC Catalyzed α-Alkylation of Methylene Ketones Provides Branched Products through Borrowing Hydrogen Strategy

Abstract

The α-alkylation of a broad range of methylene ketones was achieved using a ruthenium­(II)-NHC catalyst under borrowing hydrogen conditions. Primary alcohols served as alkylating agents and could be used in a one-to-one stoichiometry with respect to the ketone. The selectivity of the process for methyl over branched ketones enabled a one-pot double alkylation protocol utilizing two different alcohols with a single catalyst. Moreover, this methodology could be applied directly to the one-step synthesis of donepezil, the best-selling drug for the treatment of Alzheimer’s disease.

Complete lignocellulose conversion with integrated catalyst recycling yielding valuable aromatics and fuels

“…For example, 1G can be used for the synthesis of XH-14, a widely used pharmaceutically active compound for the treatment of coronary heart disease 47 . Compound 6Cy from acid 6 can be turned into anti-Alzheimer's donepezil by using commercially available reagents 48 . 12b can be used as intermediate in the synthesis of carbazole derivatives 49 .…”

Iridium Supported on Phosphorus‐Doped Porous Organic Polymers: Active and Recyclable Catalyst for Acceptorless Dehydrogenation and Borrowing Hydrogen Reaction

“…[9] In 2016, Ding and coworkers synthesized a multifunctional copolymer (PyPPh 2 À SO 3 H@porous organic polymers, POPs) through the copolymerization reaction under solvothermal conditions and the corresponding copolymersupported PdÀ PyPPh 2 À SO 3 H@POPs catalyst showed higher activities. [14] This method provides an environmentally friendly strategy to achieve the goal of sustainable and green chemistry. [8] In 2017, Zhan and Ding developed a P-doped porous organic polymer and employed it as support and ligand to achieve a novel Pd complex which has shown high efficiency in catalyzing hydrogenation reactions and resulted in high chemoselectivity.…”

“…[12,13] With this borrowing hydrogen strategy, alcohols (or amines) are simply converted in situ into the corresponding carbonyl compounds, which are much more reactive than alcohols (or amines) and could react with coupling reagents. [14] This method provides an environmentally friendly strategy to achieve the goal of sustainable and green chemistry. [15] Recently, we designed and synthesized several iridium, copper and ruthenium catalysts and explored their catalytic activity through borrowing hydrogen strategy.…”

Desarrollo de sulfuros clúster de metales del grupo seis y sus aplicaciones catalíticas

“…[61][62][63] En esta sección nos centraremos en las aplicaciones de clústeres con unidad central M3S4 y M3M'S4, de mayor interés para esta tesis doctoral.…”

“…Se han descrito numerosos ejemplos de reacciones de hidrogenación, [5,61] de alquilación [62] y de metátesis de olefinas catalizadas por complejos mononucleares de este metal. El profesor Robert Grubbs obtuvo el premio Nobel de Química en 2005, conjuntamente con los profesores Yves Chauvin y Richard R. Schrock, por su contribución a este último campo.…”