Mechanochemical, Water‐Assisted Asymmetric Transfer Hydrogenation of Ketones Using Ruthenium Catalyst

Abstract

Dedicated to the memory of Prof. Ferenc FülöpAsymmetric catalytic reactions are among the most convenient and environmentally benign methods to obtain optically pure compounds. The aim of this study was to develop a green system for the asymmetric transfer hydrogenation of ketones, applying chiral Ru catalyst in aqueous media and mechanochemical energy transmission. Using a ball mill we have optimized the milling parameters in the transfer hydrogenation of acetophenone followed by reduction of various substituted derivatives. The scope of the method was extended to carbo-and heterocyclic ketones. The scale-up of the developed system was successful, the optically enriched alcohols could be obtained in high yields. The developed mechanochemical system provides TOFs up to 168 h À 1 . Our present study is the first in which mechanochemically activated enantioselective transfer hydrogenations were carried out, thus, may be a useful guide for the practical synthesis of optically pure chiral secondary alcohols.

New Strategy for Effective Biosynthesis of Chiral Aryl Alcohols: Co-Cultivation Microbe with Natural Deep-Eutectic Solvent

“…For this study, the process mass intensity (PMI) reaction of 97.3 and 166.2 by co-cultivation strategy and conventional method was calculated. Comparatively, the work of Onisuru et al and Kolcsár, Szőllősi by using organometallic catalysts had also been assessed, with the PMI reaction of 272.6 and 2499.4, respectively. , Analysis of PMI results expressed the eco-friendliness of the co-cultivation strategy regarding other data in the literature and exhibited the potential of this novel biocatalytic method on the preparation of aryl alcohol. The analysis of green chemistry metrics on different above methods are supported in the Supporting Information Spreadsheet.…”

One-pot mechanochemical hydrogenation and acetylation of 4-nitrophenol to 4-aminophenol and paracetamol

“…18 Transfer hydrogenations of various reactants, such as carbonyls, ketones, and nitro derivatives have been increasingly discussed in the literature. 18,[20][21][22] However, a key question remains whether transfer hydrogenation is truly a preferred Green method of hydrogenation when compared to using elemental hydrogen. Indeed, transfer hydrogenation reagents suffer from pitfalls such as high cost, high molecular weight (compared to H 2 ), and the fact that elemental hydrogen tends to be involved in their main synthesis routes.…”

Mechanocatalysis: Simple and Rapid Mechanochemical Synthesis of Ammonia in Hydrogen, Nitrogen, and Water System

“…Mechanochemistry induced by a mechanical force is an efficient, simple, green, and energy-saving method for physicochemical and chemical transformations on a large scale, [17][18][19] and has been widely applied in chemical production and numerous research fields such as organic synthesis, [20][21][22] inorganic synthesis, [23][24][25] advanced energy materials, [26,27] metalorganic frameworks, [28,29] and gas synthesis. [30][31][32] Pfennig et al reported a mechanochemical method to prepare Grignard reagents from organobromides and subsequently react with gaseous CO 2 or sodium methyl carbonate to obtain aryl and alkyl carboxylic acids reaching 82 % yield.…”

“…Mechanochemistry induced by a mechanical force is an efficient, simple, green, and energy‐saving method for physicochemical and chemical transformations on a large scale, [17–19] and has been widely applied in chemical production and numerous research fields such as organic synthesis, [20–22] inorganic synthesis, [23–25] advanced energy materials, [26,27] metal‐organic frameworks, [28,29] and gas synthesis [30–32] . Pfennig et al .…”