A New and Eco‐Friendly Method for Reduction of Ketones in Water

Abstract

This paper reports a new, practical, and environmentally friendly catalytic system for reduction of the ketones to the related alcohols with efficient reaction performance in water. Catalysts were generated in situ from rhodium, ruthenium and iridium transition metal compounds with commercially available piperidines [Piperidine (L 1 ), 2-hydroxymethylpiperidine (L 2 ), 3-hydroxymethylpiperidine (L 3 ), 4-hydroxymethylpiperidine (L 4 ), 4-hydroxypiperidine (L 5 )] as bifunctional ligands. Catalyst generated from RuCl 2 (PPh 3 ) 3 and 4-hydroxymethyl piperidine have shown the best activity in aqueous media which gave a 100% product yield. RuCl 2 (PPh 3 ) 3 , has showed a better efficiency than [RuCl 2 (p-cymene)] 2 , IrCl(PPh 3 ) 3 , or RhCl(PPh 3 ) 3 in HCOOH-HCOONa buffer solution. This study was also investigated the relationship between the structure of hydroxymethyl piperidine ligands and the catalytic activity.[a] Dr.

Chemo‐ and Enantioselective Photoenzymatic Ketone Reductions Using a Promiscuous Flavin‐dependent Nitroreductase

“…A common way to obtain enantioenriched alcohols is by the asymmetric reduction of ketones. Amongst the diverse chemical methodologies for chiral alcohol synthesis, the most powerful and widely used is the asymmetric hydrogenation of prochiral ketones with hydrogen gas in combination with a metal catalyst [6,7] . The use of metal catalysts such as Ru, Ir, Rh or Ni allowed the synthesis of chiral alcohols in good yield and with high enantiopurity [8–12] .…”

“…Amongst the diverse chemical methodologies for chiral alcohol synthesis, the most powerful and widely used is the asymmetric hydrogenation of prochiral ketones with hydrogen gas in combination with a metal catalyst. [6,7] The use of metal catalysts such as Ru, Ir, Rh or Ni allowed the synthesis of chiral alcohols in good yield and with high enantiopurity. [8][9][10][11][12] However, these classic methodologies employ noxious metals and harsh reaction conditions.…”

Stable Chiral Ruthenium Complex Catalyst Based on Polymer Ionic Liquid for Asymmetric Transfer Hydrogenation of Aliphatic Ketones in Water

“…25−27 Chiral alcohols are important intermediates for the synthesis of various chiral drugs, perfumes, and pesticides, for which the asymmetric transfer hydrogenation of ketone compounds comprises a noteworthy preparation route. 28,30 Combinations of chiral ligand and transition metal are widely applied to this asymmetric transfer hydrogenation reaction. Asymmetric catalytic reduction of ketones in water has also attracted widespread attention.…”

“…Asymmetric catalytic reduction of ketones in water has also attracted widespread attention. 29,30 Cationic chiral water-soluble ligands can promote asymmetric hydrogenation of aromatic ketones in water, while the hydrogenation reduction reaction of alkyl ketones remains undeveloped due to significant challenges. 34 Chiral surfactant-type catalyst containing cation and long-chain alkanes was synthesized to achieve a micelle structure that can promote the highly reactive and selective hydrogen transfer reaction of alkyl ketones in water.…”

“…Chiral alcohols are important intermediates for the synthesis of various chiral drugs, perfumes, and pesticides, for which the asymmetric transfer hydrogenation of ketone compounds comprises a noteworthy preparation route. , Combinations of chiral ligand and transition metal are widely applied to this asymmetric transfer hydrogenation reaction. Asymmetric catalytic reduction of ketones in water has also attracted widespread attention. , Cationic chiral water-soluble ligands can promote asymmetric hydrogenation of aromatic ketones in water, while the hydrogenation reduction reaction of alkyl ketones remains undeveloped due to significant challenges . Chiral surfactant-type catalyst containing cation and long-chain alkanes was synthesized to achieve a micelle structure that can promote the highly reactive and selective hydrogen transfer reaction of alkyl ketones in water .…”