1333412-87-5Relevant academic research and scientific papers
Synthesis of pincer ruthenium RuCl(CNN)(PP) catalysts from [RuCl(μ-Cl)(η6-p-cymene)]2
Zhang, Shuanming,Baratta, Walter
, p. 3339 - 3342 (2013/07/19)
The cationic [RuCl(η6-p-cymene)(HCNNa)]Cl (1a) (HCNNa = 1-(6-arylpyridin-2-yl)methanamine) and the neutral RuCl 2(η6-p-cymene)(HCNNb) (1b) (HCNN b = 2-aminomethylbenzo[h]quinoline) complexes have been obtained by reaction of the precursor [RuCl(μ-Cl)(η6-p-cymene)] 2 with the corresponding nitrogen ligand (HCNNa and HCNNb) in THF. Complex 1a reacts cleanly with monodentate (P = PPh3) and bidentate phosphines (PP = dppb, dppf) in ethanol in the presence of NEt3, affording the pincer catalysts RuCl(CNN a)(PPh3)2 (2) and RuCl(CNNa)(PP) (PP = dppb 3, dppf 4). Similarly, the benzo[h]quinoline pincer derivative RuCl(CNNb)(dppb) (5) is obtained from 1b and dppb. Complex 3 has also been prepared in a one-pot reaction from [RuCl(μ-Cl)(η6-p- cymene)]2, HCNNa, and dppb in ethanol. Similarly, the chiral complex RuCl(CNNa)((R,S)-Josiphos) was isolated as a single stereoisomer by treatment of [RuCl(μ-Cl)(η6-p-cymene)] 2 with HCNNa and (R,S)-Josiphos in 1-butanol. Reaction of 1a and 1b with dppb affords cymene diphosphine species by displacement of the HCCN ligand.
Pincer Ru and Os complexes as efficient catalysts for racemization and deuteration of alcohols
Bossi, Gianluca,Putignano, Elisabetta,Rigo, Pierluigi,Baratta, Walter
, p. 8986 - 8995 (2011/10/31)
The pincer complexes [MX(CNN)(PP)] (M = Ru, Os; X = Cl, OTf; HCNN = 1-(6-arylpyridin-2-yl)methanamine; PP = diphosphine) have proven to efficiently catalyze both racemization and deuteration of alcohols in the presence of a base. Chiral alcohols have been racemized at 30-50 °C using 1 mol% of Ru or Os pincer complexes and 5 mol% of KOtBu in 2-propanol. Primary and secondary alcohols are efficiently deuterated at the α position, with respect to the OH group, using 2-propanol-d8 as solvent with Ru or Os pincer complexes and KOtBu at 30-50 °C. For secondary alcohols incorporation of deuterium at the β position has also been observed. In 2-propanol-d 8 the pincer complexes catalyze the simultaneous deuteration and racemization of (S)-1-phenylethanol, the two processes being strictly correlated. For both reactions much the same activity has been observed with the Ru and Os complexes. The pincer complexes display a superior activity with respect to the related compounds [MCl2(NN)(PP)] (NN = bidentate amine or pyridine ligand). The synthesis of the new complexes [MCl(CNN)(PP)] (M = Ru, 2, 4 and Os, 6, 7; PP = dppb, dppf) and [Ru(OTf)(CNN)(dppb)] (3) is also reported. The Royal Society of Chemistry 2011.
