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A novel cyano-functionalized monophosphine palladium substrate containing the ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary was synthesized from 3-chloropropionaldehyde diethylacetal via a one-pot process. The asymmetric hydrophosphination reactions between diphenylphosphine and the trans- or cis-monophosphine substrates were carried out under mild conditions, which gave the corresponding cyano-substituted chiral 1,3-bis(diphenylphosphino)propane palladium complexes with good yields and stereoselectivities. Subsequent functional group transformation reactions were conducted by successive treatment of the hydrophosphination products with Dibal-H and chemoselectively yielded the formyl- and hydroxyl-functionalized chiral 1,3-diphosphine complexes. The absolute configurations and coordination information of the novel 1,3-diphosphine complexes were analyzed by X-ray crystallography. The optically pure 1,3-bis(diphenylphosphino)propane ligands with cyano, formyl, and hydroxyl ...

Organopalladium complexes containing ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene and (R)-[1-(1-(dimethylamino)-2,2-dimethylpropyl]-2,5-dimethylbenzene as the chiral auxiliaries were used to promote the asymmetric hydrophosphination reactions between diphenylphosphine and ester- and keto-functionalized allenes in high regio- and stereoselectivites under mild conditions. The hydrophosphination reactions generated the 1,2-diphosphine ligands with chirality residing on the carbon backbone as bidentate chelates on the chiral organopalladium templates. The major isomers were isolated in appreciable yields in configurationally pure forms and characterized by means of single-crystal X-ray crystallography. The chiral auxiliaries could be removed chemoseletively by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral dichloro complexes. Subsequently, the dichloro complexes underwent ligand displacement with aqueous cyanide to generate their corresponding optical...

The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary has been used successfully to promote the asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylphosphine oxide in high stereoselectivity (only one isomer). However, the neutral dichloro palladium complex obtained upon removal of the auxiliary is very unstable and instantly decomposed to produce the arsenic elimination reaction product (3,4-dimethyl-2,4-cyclohexadienyl)diphenylphosphine oxide. However when the same reaction was promoted by the analogous platinum complex, only one stereoisomer was again obtained, but the resulting dichloro platinum complex is very stable in the solid state as well as in solution and coordinates to the platinum center as a As−O bidentate ligand, as confirmed by 1H NMR and single-crystal X-ray analysis. The enantiomerically pure As P═O hetero-bidentate ligand could be readily liberated from the dichloro platinum complex as a...

The organopalladium complex containing ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydrophosphination reactions of diphenylphosphine with (E)-1-phenyl-3-pyridin-2-yl-2-propenone and (E)-1-methyl-3-pyridin-2-yl-2- propenoate in high regio- and stereoselectivities under mild conditions. Hydrophosphination of (E)-1-phenyl-3-pyridin-2-yl-2-propenone with diphenylphosphine generated two stereoisomeric products in a ratio of 8:1 as five-membered 2-pyridylphosphine P−N bidentate chelates on the chiral naphthylamine palladium template. Using the same chiral metal template, the corresponding hydrophosphination reaction of (E)-1-methyl-3-pyridin-2-yl-2-propenoate gave only one product as a six-membered P−N bidentate chelate. The naphthylamine auxiliary could be removed chemoselectively from the template product by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral complexes. Subsequent ligand disp...

Ester- and keto-functionalized allylic monophosphine palladium complexes containing ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary were synthesized via a versatile one-pot process. Subsequent asymmetric hydrophosphination of the coordinated allylic substrates promoted by the chiral auxiliary gave the corresponding functionalized chiral 1,2-bis(diphenylphosphino)ethane ligands in high yields under mild conditions. The coordination properties and absolute configurations of the resultant diphosphine ligands were established by single-crystal X-ray crystallography. The coordinated 1,2-diphosphine ligands could be subsequently liberated stereospecifically to yield enantiomerically pure functionalized diphosphines in high yields.