Baratta, Walter et al. published their research in Organometallics in 2005 | CAS: 77876-39-2

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Formula: C29H30P2

2-(Aminomethyl)pyridine-Phosphine Ruthenium(II) Complexes: Novel Highly Active Transfer Hydrogenation Catalysts was written by Baratta, Walter;Herdtweck, Eberhardt;Siega, Katia;Toniutti, Micaela;Rigo, Pierluigi. And the article was included in Organometallics in 2005.Formula: C29H30P2 This article mentions the following:

Trans,cis-RuCl2(PPh3)2(ampy) (1) and trans-RuCl2[Ph2P(CH2)4PPh2](ampy) (2) were prepared in high yield by reaction of RuCl2(PPh3)3 and RuCl2(PPh3)[Ph2P(CH2)4PPh2] with 2-(aminomethyl)pyridine (ampy) at room temperature by PPh3 displacement. Heating compound 1 in refluxing toluene leads to the isomer cis,cis-RuCl2(PPh3)2(ampy) (3), which was proven to be a good precursor for the preparation of cis-RuCl2(PP)(ampy) [PP = (S,S)-Chiraphos, 4; Ph2P(CH2)3PPh2, 5; (S,S)-Skewphos, 6; Ph2P(CH2)4PPh2, 7; (R,R)-Diop, 8] by displacement of two PPh3 with the appropriate diphosphine. Cis-RuCl2(PP)(ampy) [PP = (R,S)-Josiphos, 9; (R,S)-tBu-Josiphos, 10] were synthesized from RuCl2(PPh3)3 and PP followed by addition of ampy. The chiral complexes 4, 6, 8, 9, and 10 are formed stereoselectively, as inferred by NMR data in solution For the derivatives 7 and 9 the mol. structures were determined by x-ray measurements. The monohydride complex trans,cis-RuHCl(PPh3)2(ampy) (11) was prepared from RuHCl(PPh3)3 and ampy in heptane by PPh3 substitution. Compound 11 reacts with Na isopropoxide in toluene, affording the dihydride derivative cis,trans-Ru(H)2(PPh3)2(ampy) (12) via the alkoxide route. The intermediate species cis,cis-Ru(H)2(PPh3)2(ampy) (A) was also characterized by NMR in solution All these complexes are highly efficient transfer hydrogenation catalysts. With cis-RuCl2(PP)(ampy) a large number of ketones (dialkyl, diaryl, and alkyl-aryl) can be quant. reduced to alcs. in iso-PrOH and in the presence of NaOH (ketone/Ru/NaOH = 2000/1/40) with remarkably high TOF values (up to 400,000 h-1 at 50% conversion). The derivatives containing chiral diphosphines afforded rapid (TOF > 105 h-1) and enantioselective (ee up to 94%) reduction of Me-aryl ketones using low loading of catalysts (0.05-0.01 mol %). In the absence of base the dihydride compound 12 catalyzes the transfer hydrogenation of acetophenone. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Formula: C29H30P2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Formula: C29H30P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis