450368-81-7

Upstream product

• 24424-99-5 di-tert-butyl dicarbonate 
• 450368-80-6 N-((1R,2R)-2-amino-1,2-diphenylethyl)-4-nitrobenzenesulfonamide 
• 98-74-8 4-Nitrobenzenesulfonyl chloride 

Downstream Products

• 450368-83-9 {(1R,2R)-2-[4-(2-Benzyloxycarbonylamino-acetylamino)-benzenesulfonylamino]-1,2-diphenyl-ethyl}-carbamic acid tert-butyl ester 
• 450368-84-0 {(1R,2R)-2-[4-(2-Amino-acetylamino)-benzenesulfonylamino]-1,2-diphenyl-ethyl}-carbamic acid tert-butyl ester 
• 450368-82-8 (R,R)-N-tert-butoxycarbonyl-N'-(4-aminophenylsulfonyl)-1,2-diphenylethylenediamine 

Relevant academic research and scientific papers

Ruthenium(II)-catalyzed asymmetric transfer hydrogenation of aromatic ketones in water using novel water-soluble chiral monosulfonamide ligands

Novel water-soluble analogues of Noyori's (R,R)-N-(p-tolylsulfonyl)-1,2- diphenylethyl- enediamine and Knochel's (R,R)-N-(p-tolylsulfonyl)-1,2- diaminocyclohexane, containing an additional quaternary ammonium group, have been synthesized. The ruthenium catalysts prepared in situ by reacting chiral monosulfonamides with [RuCl2(p-cymene)]2 afforded high conversion rates and enantiomeric excess (ee) values in the asymmetric transfer hydrogenation of aromatic ketones in aqueous HCOONa. Furthermore, the catalyst could be easily recovered and reused at least five times without obvious loss of ee value.

Multiple dendritic catalysts for asymmetric transfer hydrogenation

The first and second generation multiple dendritic ligands based on chiral diamine were synthesized in a convergent approach and were well-characterized by NMR and MS techniques. Their ruthenium complexes prepared in situ had good solubility in the reaction medium (azeotrope of formic acid and triethylamine) and demonstrated high catalytic activity and enantioselectivity comparable to monomeric catalysts in the asymmetric transfer hydrogenation of ketones and imines. Quantitative yields and for some cases a slightly higher enantioselectivity (up to 98.7% ee) were obtained in the dendritic catalysis. Considering the high local catalyst concentrations at the periphery, diones were tested for the possible synergic reactivity between catalytic units at the surface, while no apparent differences were noted.