Two highly air-sensitive asymmetric ligands (+/-)-diphenyl[1-(1-naphthyl)ethyl]phosphine and its arsenic analogue [(+/-)-L] have been prepared and resolved by the fractionalization of a pair of diastereomeric palladium complexes containing the appropriate ligand and ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthylene. X-ray structural analysis revealed that the less soluble isomers in each resolution contained the resolving ligand of the S absolute configuration. The resolved ligands coordinated as monodentates with only the phosphorus or arsenic donor coordinated to the resolving organopalladium unit. Due to the steric congestions between the phenyl and the naphthyl rings, the Ph(2)E-C distances in both monodentate ligands are unusually long [1.885(2) A for E = P and 2.035(7) A for E = As]. The (R)-naphthylamine auxiliary could be removed chemoselectively from the resolved complexes by treatment with concentrated hydrochloric acid to give the corresponding bis(micro-chloro) complexes (-)-[(S)-LPdCl(2)](2). Treatments of these dimeric complexes with sodium acetate in ethanol gave the novel ortho-metalated complex bis(micro-chloro)bis[(S)-1-[1-(diphenylphospha)ethyl]naphthylenyl-C(2),P]dipalladium(II), with [alpha](D) +559 degrees (CH(2)Cl(2)), and the analogous ortho-metalated (S)-arsa complex, with [alpha](D) +349 degrees (CH(2)Cl(2)). The Ph(2)E-C distances recorded for the ortho-metalated phosphine complex are 1.841(6) and 1.846(5) A, and those recorded for the organometallic arsa rings are 1.938(9) and 1.945(9) A. These Ph(2)E-C distances are noticeably shorter than those recorded for their analogous monodentate complexes. The intrachelate E-Pd-C angles of the analogous amino, phospha, and arsa complexes involved in the current study are similar [within the range of 80.5(2)-82.1(3) degrees ] although it is noticeable that As > P > N.

An organopalladium complex containing ortho-metalated (S)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydrophosphination reactions between diphenylphosphine and (E)- or (Z)-diphenyl-1-propenylphosphine in high regio- and stereoselectivities under mild conditions. Hydrophosphination of (Z)-diphenyl-1-propenylphosphine with diphenylphosphine gave (S)-(-)-prophos as the major product. Using the same chiral metal template, the corresponding hydrophosphination reaction with (E)-diphenyl-1-propenylphosphine gave (R)-(+)-prophos predominantly. The hydrophosphination reactions generated the asymmetric diphosphines as bidentate chelates on the chiral naphthylamine palladium templates. The template products obtained undergo cis-trans isomerization in solution to form an equilibrium mixture of regioisomers. X-ray analysis of the major template products obtained from the hydrophosphination of (Z)-diphenyl-1-propenylphosphine reveals that the two regioisomers are cocrystallized in a 1:1 ratio. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral complexes [(R)- or (S)-(prophos)PdCl(2)]. Subsequently, the (R)- and (S)-dichloro complexes undergo ligand displacement with aqueous cyanide to generate the corresponding optically pure diphosphine ligands in high yields. Mechanistic pathways explaining the stereoselectivity of the chiral organopalladium template promoted hydrophosphination reactions are also proposed.

An organoplatinum complex containing ortho-metalated (S)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric [4 + 2] Diels-Alder reaction between diphenylvinylphosphine and N-(diphenylphosphino)pyrrole. The reaction was complete in 7 days at room temperature, with the formation of three isomeric chelating diphosphine exo cycloadducts in the ratio 10:3:1. The cycloadducts are thermodynamically unstable and undergo retro-cycloaddition reactions slowly in solution. When the major isomer of the pyrrole cycloadducts was heated with 2-(diphenylphosphino)furan, the respective furan cycloadducts were formed via the retro pyrrole Diels-Alder pathway, followed by an asymmetric furan Diels-Alder reaction. The cyclic diene N-(diphenylphosphino)pyrrole was regenerated from this retro cycloaddition reaction. The undesired retro Diels-Alder reaction could be deterred by hydrogenation of the azanorbornene double bond. The chiral naphthylamine auxiliary could be removed chemoselectively from the metal template by treatment with concentrated hydrochloric acid to generate the corresponding dichloroplatinum(II) complex. The azabicyclic skeleton and the P-N bond remained unchanged in this acid treatment. Further treatment of the dichloro complex with aqueous cyanide liberates the chiral diphosphine cycloadduct, which could be coordinated to the Au-(I) metal ion.

A series of enantiomerically pure organopalladium complexes containing the resolved orthometalated (R/S)-N,N-dimethyl-1-(9-phenanthryl)ethylamine ligand have been prepared. The absolute ring conformations of these novel organometallic phenanthrylamine chelates in the solid state and in solution have been investigated by X-ray structural analyses and 2D ROESY NMR spectroscopy, respectively. All the chiral ortho-metalated rings were found to be stereochemically rigid, with their absolute ring conformations being locked by the repulsive interactions between the methyl group on the chiral carbon and the adjacent aromatic proton H8 of the phenanthrylamine ring. The methyl substituents on the stereogenic carbons invariably take up the axial positions in the skewed five-membered rings such that the static δ and λ ring conformations are adopted by the R-and S-phenanthrylamine, respectively. Despite the enormous interchelate steric constraints, the monodentates PPh 3 and DMPP are coordinated regiospecially to the ortho-palladated phenanthrylamine unit trans to the NMe 2 group. The organometallic rings are able to adopt distorted tetrahedral geometries around their palladium atoms and even alter their conjugated phenanthryl planarities in order to accommodate bulky ligands including DMPP, PPh 3 , and N,N,N′,N′-tetramethyl-2,3-butanediamine. Compared with its naphthylamine analogue, the ortho-palladated phenanthrylamine unit shows a much higher stereoselectivity in the chiral templatepromoted asymmetric cycloaddition reaction between DMPP and N,N-dimethylacrylamide.