In situ formation of ligand and catalyst—application in ruthenium-catalyzed enantioselective reduction of ketones

Abstract

The direct in situ formation of highly efficient ruthenium-catalysts for the asymmetric reduction of ketones was obtained by combining chiral ligand building blocks with a ruthenium precursor.

Rhodium‐Catalyzed Asymmetric Transfer Hydrogenation of Aryl Alkyl Ketones Employing Ligands Derived from Amino Acids

“…Ru(II) and RhA C H T U N G T R E N N U N G (III) half-sandwich complexes are generally thought to form active catalysts for ATH when combined with 1,2-amino alcohols or monotosylated 1,2-diamines, containing a basic primary or secondary amino group in the b-position to a relatively acidic OH or NH group. [23] N-Boc-protected amino acid hydroxyamide (in our previous papers and later on in this study referred to as pseudodipeptide) ligands (1) [24][25][26][27][28][29] previously developed by us represent a different class of ligands without an explicit basic nitrogen center. Instead, we have demonstrated that alkali ions play a crucial role in the hydrogen transfer step employing catalysts derived from such ligands.…”

Metal Complexes of Biologically Important Ligands, CLXXVI.[1] Formation of Peptides within the Coordination Sphere of Metal Ions and of Classical and Organometallic Complexes and Some Aspects of Prebiotic Chemistry

“…The ruthenium half‐sandwich complex with the in situ formed pseudo‐dipeptide as ligand has been proven as highly effective catalyst for the asymmetric reduction of ketones46 (Scheme , Equation (10)).…”

Combinatorial Transition‐Metal Catalysis: Mixing Monodentate Ligands to Control Enantio‐, Diastereo‐, and Regioselectivity

“…[6,29] For example, Adolfsson has described a concept in which in situ formation of modular ligands as well as catalyst formation and reaction are possible in an integrated system.…”

“…[22a] The concept of utilizing libraries of modular ligands for asymmetric transition-metal catalysis was also championed by Burgess, [23] Gilbertson, [24] Kobayashi, [25] Waldmann, [26] Berkessel, [27] Schmalz, [28] Ding, [6f] and others. [6,29] For example, Adolfsson has described a concept in which in situ formation of modular ligands as well as catalyst formation and reaction are possible in an integrated system. [29a] Moreover, de Vries and co-workers at DSM have published informative reviews of high-throughput methods in asymmetric hydrogenation and other reactions.…”