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The intramolecular Pd-catalyzed carboetherification of alkenes affords 2-indan-1-yltetrahydrofuran products in moderate to good yield with good to excellent levels of diastereoselectivity. The stereochemical outcome of these reactions is dependent on the structure of the Pd catalyst. Use of PCy(3) or P[(4-MeO)C(6)H(4)](3) as the ligand for Pd leads to syn-addition of the arene and the oxygen atom across the double bond, whereas use of (+/-)-BINAP or DPP-benzene affords products that result from anti-addition. The catalyst-induced change in stereochemistry is likely due to a change in reaction mechanism. Evidence is presented that suggests the syn-addition products derive from an unprecedented transannular alkene insertion of an 11-membered Pd(Ar)(OR) complex. In contrast, the anti-addition products appear to arise from Wacker-type anti-oxypalladation. Studies on analogous Pd-catalyzed intramolecular carboamination reactions, which afford 2-indan-1-ylpyrrolidines that result from syn-addition, are also described.

A strategy for the stereoselective preparation of enantiomerically enriched cis -2,6-disubstituted piperazines from amino acid precursors is described. The target compounds are generated in 95–99% ee with good to excellent levels of diastereoselectivity (usually 14:1 to >20:1) using Pd-catalyzed carboamination reactions between aryl or alkenyl halides and substituted ethylenediamine derivatives to form the heterocyclic rings. The synthesis requires only 4–5 steps from commercially available amino acids, and allows for the modular construction of piperazines bearing different substituents at N 1 , N 4 , C 2 , and C 6 . The use of this strategy for the construction of 2,3-disubstituted piperazines, fused bicyclic piperazines, and tetrahydroquinoxalines is also reported. In addition, the mechanism of the key carboamination reactions is discussed, and new models that predict and explain the stereochemical outcome of these transformations are presented.

A strategy for the stereoselective preparation of enantiomerically enriched cis -2,6-disubstituted piperazines from amino acid precursors is described. The target compounds are generated in 95–99% ee with good to excellent levels of diastereoselectivity (usually 14:1 to >20:1) using Pd-catalyzed carboamination reactions between aryl or alkenyl halides and substituted ethylenediamine derivatives to form the heterocyclic rings. The synthesis requires only 4–5 steps from commercially available amino acids, and allows for the modular construction of piperazines bearing different substituents at N 1 , N 4 , C 2 , and C 6 . The use of this strategy for the construction of 2,3-disubstituted piperazines, fused bicyclic piperazines, and tetrahydroquinoxalines is also reported. In addition, the mechanism of the key carboamination reactions is discussed, and new models that predict and explain the stereochemical outcome of these transformations are presented.

A concise, modular, asymmetric synthesis of cis-2,6-disubstituted piperazines from readily available amino acid precursors is described. The key step in the synthesis is a Pd-catalyzed carboamination of a N1-aryl-N2-allyl-1,2-diamine with an aryl bromide. The products are obtained in 14−20:1 dr, with >97% ee, and the key cyclizations are the first examples of six-membered ring formation via Pd-catalyzed carboamination reactions of unsaturated amines with aryl halides.

A concise, modular, asymmetric synthesis of cis-2,6-disubstituted piperazines from readily available amino acid precursors is described. The key step in the synthesis is a Pd-catalyzed carboamination of a N1-aryl-N2-allyl-1,2-diamine with an aryl bromide. The products are obtained in 14−20:1 dr, with >97% ee, and the key cyclizations are the first examples of six-membered ring formation via Pd-catalyzed carboamination reactions of unsaturated amines with aryl halides.

A new strategy for the preparation of substituted imidazolidin-2-ones in two steps from readily available N-allylamines is described. Addition of the amine starting materials to isocyanates affords N-allylureas, which are converted to imidazolidin-2-one products with generation of two bonds and up to two stereocenters when treated with aryl bromides and catalytic amounts of Pd2(dba)3/Xantphos in the presence of NaO(t)Bu. [reaction: see text]