Synthesis of Pincer Ruthenium RuCl(CNN)(PP) Catalysts from [RuCl(μ-Cl)(η⁶-p-cymene)]₂

Abstract

The cationic [RuCl(η 6 -p-cymene)(HCNN a )]Cl (1a) (HCNN a = 1-(6-arylpyridin-2-yl)methanamine) and the neutral RuCl 2 (η 6 -p-cymene)(HCNN b ) (1b) (HCNN b = 2aminomethylbenzo[h]quinoline) complexes have been obtained by reaction of the precursor [RuCl(μ-Cl)(η 6 -pcymene)] 2 with the corresponding nitrogen ligand (HCNN a and HCNN b ) in THF. Complex 1a reacts cleanly with monodentate (P = PPh 3 ) and bidentate phosphines (PP = dppb, dppf) in ethanol in the presence of NEt 3 , affording the pincer catalysts RuCl(CNN a )(PPh 3 ) 2 (2) and RuCl(CNN a )(PP) (PP = dppb 3, dppf 4). Similarly, the benzo[h]quinoline pincer derivative RuCl(CNN b )(dppb) ( 5) is obtained from 1b and dppb. Complex 3 has also been prepared in a one-pot reaction from [RuCl(μ-Cl)(η 6 -p-cymene)] 2 , HCNN a , and dppb in ethanol. Similarly, the chiral complex RuCl(CNN a )((R,S)-Josiphos) was isolated as a single stereoisomer by treatment of [RuCl(μ-Cl)(η 6 -p-cymene)] 2 with HCNN a and (R,S)-Josiphos in 1-butanol. Reaction of 1a and 1b with dppb affords cymene diphosphine species by displacement of the HCCN ligand.

Binding structures of tri‐N‐acetyl‐β‐glucosamine in hen egg white lysozyme using molecular dynamics with a polarizable force field

“…[23, 24] The polarizable force field for the ligand based on the CHEQ model (shown in Tables 1–3, Supporting Information), (NAG) 3 , was developed and the hydration free energy, and other solution properties were analyzed in our previous work. [22]…”

“…Recently, we developed a polarizable force field for NAG molecule and compared with an existing fixed‐charge force field (see Ref. [22]). Here, we apply the polarizable (nonadditive electrostatic) model along with a polarizable protein force field[23, 24] to study the binding structure of HEWL–(NAG) 3 .…”

Transfer Hydrogenation from 2-propanol to Acetophenone Catalyzed by [RuCl2(η6-arene)P] (P = monophosphine) and [Rh(PP)2]X (PP = diphosphine, X = Cl−, BF4−) Complexes

“…At present, many highly efficient Ru-phosphorus systems for the TH reduction of ketones and aldehydes in the presence of 2-propanol and other H-donors (i.e., HCOOH/NEt 3 mixtures, HCOONa, HCOONH 4 ) have been reported. Within these catalytic systems, stand out the precursors developed by Noyori et al containing the BINAP motif [39][40][41] as well as Ru complexes bearing cyclometallated phosphines [42,43], or other ligands as fluoroacetate [44], bi-and tridentate nitrogen ligands in combination with mono- [45] or diphosphines, developed by Baratta et al [46][47][48][49]. The association of chiral phosphorus ligands with (chiral) primary or secondary amine functionalities (bifunctional catalysts) often results in elevated enantioselectivities [50].…”

Ruthenium and osmium complexes containing 2-(aminomethyl)pyridine (Ampy)-based ligands in catalysis

“…We very recently reported a practical route for the preparation of CNN pincer catalysts starting from [RuCl(-Cl)( 6 -p-cymene)] 2 (69) (Schemes 38 and 39) [39]. Treatment of 69 with 2 equiv.…”