Synthesis And Characterization Of Carbohydrate-Based Chiral Phosphines And Their Pd(Ⅱ)、Pt(Ⅱ) Complexes

Synthesis of new chiral phosphines is fundamentally important for the chiral catalysis and the chiral catalytic techniques with independent intellectual property r ights. In recent decades, some chiral phosphines derived from natural chiral source have achieved very good results for asymmetric catalytic reactions. Sugar molecul es relatively complex, with multiple chiral centers and functional groups, is a very attractive chiral source. Tremendous progresses have been revealed by Pd(II) and Pt(II) complexes of chiral phosphine in asymmetric catalytic reactions, including f ine chemical and pharmaceutical fields. Therefore, it makes sense to synthesize car bohydrate-based chiral phosphine and their Pd(Ⅱ)、Pt(Ⅱ) complexes.A BH3protected chiral phosphine (1-1,(methyl4,6-O-benzylidene-3-deoxy-α-D-altropyranosido-3-)-diphenyl phosphine-boranes) has been prepared in one pot by reacting methyl2,3-anhydro-4,6-O-benzylidene-3-a-D-mannopyranoside with LiPPh2and BH3, respectively. Deproton of hydroxyl by NaH, followed by methylation with Mel, afforded a BH3protected phosphine (1-2). Deprotection of BH3with et hanol to furnish the desired free phosphine1-3.A Pd(Ⅱ) complex2-1and cis-and trans-[PtCl2(1-3)2] complexes (3-1,3-2) ha ve been prepared from the chiral phosphine ligand1-3. The geometry configuratio n of the Pt(Ⅱ) sources is highly retained in their corresponding products with the carbohydrate-based phosphine1-3.Two trans-[PtCl2(L)2] complexes4-1,4-2, have been synthesized from (Rp)-and (Sp)-(methyl2-O-methyl-4,6-O-benzylidene-3-deoxy-α-D-altropyranosido-3-)-phe nylmethylphosphine-boranes, respectively.