1071069-49-2

Upstream product

• 1079-66-9 chloro-diphenylphosphine 
• 20469-65-2 1-bromo-3,5-dimethoxybenzene 
• 1365320-08-6 (3,5-dimethoxyphenyl)diphenylphosphine oxide 
• 1365320-10-0 (2-bromo-3,5-dimethoxyphenyl)diphenylphosphine oxide 

Downstream Products

• 1365531-75-4 (R)-4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl-bis(diphenylphosphine) 
• 1365531-75-4 (S)-4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl-bis(diphenylphosphine) 

Relevant academic research and scientific papers

Biaryl diphosphine ligands and their ruthenium complexes: Preparation and use for catalytic hydrogenation of ketones

Procedures for the preparation of the nucleophilic diphosphine ligands (R)-(4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine) ((R)-Ph-Garphos, 2a) and (S)-(4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine) ((S)-Ph-Garphos, 2b) were described. The ligands were used to prepare the ruthenium(II) Ph-Garphos complexes, chloro(p-cymene)(R)-(4,4′,6,6′-tetraamethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine)ruthenium(II) chloride ([RuCl(p-cymene)(R)-Ph-Garphos]Cl (3)) and chloro(p-cymene)(S)-(4,4′,6,6′-tetraamethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine)ruthenium(II) chloride ([RuCl(p-cymene)(S)-Ph-Garphos]Cl (4)). In the presence of the chiral diamine co-ligands (1R,2R)-1,2-diphenylethane-1,2-diamine (R,R-DPEN) and (1S,2S)-1,2-diphenylethane-1,2-diamine (S,S-DPEN), complexes 3 and 4 were found to be catalyst precursors for the enantioselective reduction of aryl ketones under mild conditions (room temperature and 3–4 atm of H2). The chiral alcohols were isolated in moderate to good yields and with enantioselectivities of up to 93percent. The ruthenium complexes chloro(p-cymene)(R)-(4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl)bis(bis(3,5-dimethylphenyl)-phosphine)ruthenium(II) chloride ([RuCl(p-cymene)(R)-Xyl-Garphos]Cl (5)) and chloro(p-cymene)(S)-(4,4′,6,6′-tetramethoxybiphenyl-2,2′-diyl)bis(bis(3,5-dimethylphenyl)-phosphine)ruthenium(II) chloride ([RuCl(p-cymene)(S)-Xyl-Garphos]Cl (6)) were also prepared and used as catalyst precursors for the hydrogenation of aryl ketones in the presence of (R,R)-DPEN and (S,S)-DPEN. Significant improvements in the enantioselectivities of the alcohols (up to 98percent ee.) were afforded. A combination of 6 and (S,S)-DPEN afforded (R)-1-(3-methoxyphenyl)ethanol in 89percent yield and with 95percent ee which was shown to be a suitable precursor for the preparation of (S)-rivastigmine.

BIARYL DIPHOSPHINE LIGANDS, INTERMEDIATES OF THE SAME AND THEIR USE IN ASYMMETRIC CATALYSIS

The present disclosure relates to biaryl diphosphine ligands of the formula (B), processes for the production of the ligands and the use of the ligands in metal catalysts for asymmetric synthesis. The disclosure also relates to intermediates used for the production of the biaryl diphosphine ligand. (Formula (B))