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The organopalladium complex containing ortho-metallated (S)-[1-(dimethylamino)ethyl]naphthalene as a chiral auxiliary has been successfully employed to promote the asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylarsine. In the intramolecular cycloaddition reaction, a pair of separable diastereomeric palladium complexes was obtained in the ratio of 6:1. The chiral naphthylamine auxiliary could be removed chemoselectively from the template by treatment with HCl and subsequently NaI to generate the neutral diiodo complex [(As-As)PdI2]. Treatment of the diiodo complex with KCN gave the enantiomerically pure As-As bidentate ligand in quantitative yield. In contrast to the reported similar P-P and As-P analogues, both arsenic donors in the diiodo complex could be readily eliminated to produce a structurally novel dimetallic complex. [ABSTRACT FROM AUTHOR]

The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]phenylene as the chiral auxiliary has been used as the chiral template to promote the asymmetric cycloaddition reaction between diphenylvinyiphos- phine and 3,4-dimethyl-1-phenylarsole. A diphenylphosphino-substituted asymmetrical heterobidentate arsanorbornene (As-P) ligand was obtained stereoselectively on the chiral palladium template in moderate yield. The chiral benzylamine auxiliary could be removed chemoselectively from the template by treatment with HCl to produce the neutral complex [(As-P)PdCl2]. In contrast to their reported P-P analogue, the arsenic donor in the dichloro complex could be eliminated stereospecifically under mild reaction conditions to generate the corresponding 1-(diphe- nylphosphino)-3,4-dimethyl-2,4-cyclohexadiene, which remained as a bidentate ligand at the PdCl2 unit via phosphorus and the η²-C4-C5 double bond. The arsenic-elimination process was found to be influenced by the halo ligand in [(As-P)PdX2]. A similar process was observed with the analogous dibromo complex, but the corresponding diiodo species did not show similar reactivity. All of the novel As-Pd complexes have been characterized by X-ray crystallography. [ABSTRACT FROM AUTHOR]