| Chiral BINAP,as a full aromatic ring-substituted diphosphine compound,is one of paramount chiral biphosphine ligands.It possesses C2 axial symmetry,flexible molecular pliancy,and good coordination ability which endow its complexes of ruthenium,rhodium and palladium with excellent chiral recognition and selection profile in numerous asymmetric catalytic reaction including hydrogenation,hydrocyanation,cyanosilylation,disilylation,Heck reaction,14,-addition reaction.In the dissertation,a new route was developed to improve the synthetic efficiency of chiral BINAP.The first step is the reaction of cinchonidine with benzyl chloride to produce a resolving agent?8S,9R?-?-?-N-benzylcinchonidinium chloride,and then the agent is used to resolve racemic binaphthol?abbreviated to BINOL?in order to obtain optical pure 1,1'-Bi-2-naphthol.Mixing pure 1,1'-Bi-2-naphthol with trifluoromethanesulfonic anhydride in pyridine gives rise to chiral ditriflate of binaphthol?abbreviated to BINOL-OTf?,which is finally converted to optical pure BINAP by coupling with Ph2 PH in the presence of NiCl2·dppe.The overall yield is up to 65% with 98.0% ee.All chemical structures of the intermediates formed in the synthetic process were confirmed by 1H NMR,13 C NMR and 31 P NMR.Three platinum group metal-based complexes of chiral BINAP,[Ru??S?-BINAP??OAc?2],[Rh??S?-BINAP??COD?]ClO4,[Pd??S?-BINAP?Cl2],were prepared,respectively,from [Ru?COD?Cl2]n,[Rh?COD?Cl)]2 and [Pd?COD?Cl2] via the reactions with chiral BINAP.The corresponding yield was calculated to be 94.5% for [Ru??S?-BINAP??OAc?2],97.4% for [Rh?S?-BINAP)?COD?]ClO4 and 98.3% for [Pd??S?-BINAP?Cl2],greater than the data reported in the literatures.The chemical structures of these complexes were verified by mass spectral?MS?,infrared spectral?IR?and nuclear magnetic resonance(1H NMR?31P NMR)measurements along with X-ray single crystal diffraction analysis.The chemical structures are illustrated in the following figures. |
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