928207-58-3

Upstream product

• 52462-29-0 [ruthenium(II)(η⁶-1-methyl-4-isopropyl-benzene)(chloride)(μ-chloride)]₂ 
• 882050-76-2 [(S)-Me₃SiCH₂P(Ph)(2-biphenylyl)] 
• 882050-76-2 (S)-(2-biphenylyl)(2,2-dimethyl-2-silapropyl)phenylphosphine 

Relevant academic research and scientific papers

Neutral p-cymene ruthenium complexes with P-stereogenic monophosphines. New catalytic precursors in enantioselective transfer hydrogenation and cyclopropanation

A family of eight neutral, pseudotetrahedral piano-stool ruthenium complexes C, of the type [RuCl2(p-cymene)(PArPhR)] (Ar = 1-naphthyl, 9-phenanthryl and 2-biphenylyl; R = Me, i-Pr, OMe, -CH2SiMe 3 and -CH2SiPh3) have been prepared and characterised, including the X-ray crystal structure for C6 (Ar = 2-biphenylyl; R = i-Pr). These complexes catalyse the asymmetric hydrogen transfer reaction of acetophenone in refluxing 2-propanol in the presence of potassium tert-butoxyde, reaching full conversions and up to 45% ee after 24 h towards the S enantiomer of 1-phenylethanol. Cationic complexes formed upon treatment of C with one equivalent of AgSbF6 or (Et3O)PF6 are active in the cyclopropanation reaction of styrene and α-methylstyrene by ethyl diazoacetate. Low to moderate conversions (up to 58%), diastereoselectivities (up to 40% de), and moderate enantioselectivities (up to 69% ee) have been found. For both reactions, bulky complexes and C6 in particular lead to the best results.

Rhodium or ruthenium units peripherally coordinated to carbosilane dendrimers functionalized with P-stereogenic monophosphines

Carbosilane dendrimers containing P-stereogenic monophosphines as terminal groups, Dend-{CH2PPhR}n (R = 2-biphenylyl or 9-phenanthryl), were reacted with [RhCl(COD)]2 or [RuCl2(p-cymene)]2 to afford the corresponding chiral metalladendrimers Dend-{CH2PPhR(RhCl(COD))}n or Dend-{CH2PPhR(RuCl2(p-cymene))}n, respectively. Attempts to obtain the first generation Ru-dendrimer for R = 2-biphenylyl proved unsuccessful, probably due to the steric hindrance of R. Complete characterization of these species was achieved by multinuclear NMR spectra, including 2D experiments, mass spectrometry, and optical rotation determinations. The catalytic properties of the rhodium dendrimers were tested in the hydrogenation of dimethylitaconate and those of the ruthenium derivatives in the asymmetric hydrogen transfer of acetophenone. The following model chiral compounds, (CH3)3Si{CH2PPhR(RhCl(COD))} and (CH3)3Si{CH2PPhR(RuCl2(p-cymene))}, were prepared in order to detect potential dendritic effects. All compounds were active in the catalytic conditions tested, but low or null e.e. were found.