Novel 2-alkyl- or 2-aryl-4,5-(4,6-O-benzylidene-3-O-(diphenylphosphino)-1,2-dideoxy-α-d-glucopyrano)-[2,1-d]-2-oxazolines (5a−f) have been prepared from d-glucosamine hydrochloride. They work effectively as chiral ligands and provide a high level of enantiomeric excess in palladium-catalyzed allylic alkylation and amination reactions. The allylic alkylation of 1,3-diphenyl-3-acetoxyprop-1-ene with dimethyl malonate proceeds smoothly in the presence of 0.25 mol % [Pd(η3-C3H5)Cl]2 and the chiral ligand 5a having the smallest substituent on oxazoline at 0 °C within 6 h to furnish the highest enantiomeric excess (96% ee). The ligand 5a is also effective for the Pd-catalyzed amination of ethyl 1,3-diphenylprop-2-enyl carbonate, leading to the corresponding allylic amine in 94% ee. The full scope and limitations using ligands 5a − f in the allylic substitution reactions are described.

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Novel 2,3:4,6-di-O-isopropylidene-alpha-D-glucopyranosyl-(1,1)-4,6-O-isopropylidene-2,3-di-O-diphenylphosphino-alpha-D-glucopyranoside (2), 2,3:4,6-di-O-cyclohexylidene-alpha-D-glucopyranosyl-(1,1)-4,6-O-cyclohexylidene-2,3-di-O-diphenylphosphino-alpha-D-glucopyranoside (4), and 2,3:4,6-di-O-cyclohexylidene-beta-D-glucopyranosyl-(1,1)-4,6-O-cyclohexylidene-2,3-di-O-diphenylphosphino-beta-D-glucopyranoside (11) were prepared from the corresponding alpha,alpha- or beta,beta-trehalose. The ligands were transformed into cationic Rh complexes, such as [Rh(alpha-D-glucopyranosyl-(1,1)-2,3-di-O-diphenylphosphino-alpha-D-glucopyranoside)(cod)]BF(4) (3) and [Rh(beta-D-glucopyranosyl-(1,1)-2,3-di-O-diphenylphosphino-beta-D-glucopyranoside)(cod)]BF(4) (12) bearing free hydroxy groups. These complexes were soluble in water and were efficient catalysts for the asymmetric hydrogenation of dehydroamino acids and their esters in water or an aqueous/organic biphasic medium with high enantioselectivity (up to 99.9% ee). Aqueous biphasic systems offer an easy separation of the aqueous catalyst phase from the product phase and allow recycling of the catalyst phase without the loss of enantioselectivity.

A novel amphiphilic phosphinite-oxazoline chiral compound, 2-methyl-4,5-[4,6-O-benzylidene-3-O-bis[4-((diethylamino)methyl)phenyl]phosphino-1,2-dideoxy-alpha-D-glucopyranosyl]-[2,1-d]-2-oxazoline (1), has been prepared from natural D-glucosamine hydrochloride. The newly prepared complex, [Pd(2-methyl-4,5-[4,6-O-benzylidene-3-O-bis[(4-((diethylmethylammonium)methyl)phenyl)]phosphino-1,2-dideoxy-alpha-D-glucopyranosyl]-[2,1-d]-2-oxazoline)(eta3-C3H5)]3+ x 3BF4- (3), is soluble in water and an efficient catalyst for asymmetric allylic substitution reaction in water or an aqueous/organic biphasic medium (up to 85% ee). This catalytic system offers an easy separation of the aqueous catalyst phase from the product phase and allows recycling of the catalyst phase. In addition, compound 1 also works as an effective ligand for the palladium-catalyzed reaction under conventional homogeneous conditions in an organic medium, in which the catalyst (Pd-1 complex) can be recovered by simple acid/base extraction and reused in the second reaction.

Novel phosphinite-nitrogen chiral ligands synthesized from d-glucosamine furnish a high level of enantiomeric excess (up to 96% ee) in palladium-catalysed allylic alkylation.