A series of fused tetracycles with a benzene or cyclohexadiene core (2a-h) is satisfactorily prepared by intramolecular [2 + 2 + 2] cycloadditions of triynic and enediynic macrocycles (1a-h) under RhCl(PPh3)3 catalysis; the enantioselective cycloaddition of macrocycles 1b and 1e and gives chiral tetracycles with moderate enantiomeric excess.

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A series of nickel(0) complexes, 3, 4, and 5, containing unsaturated 15-membered azamacrocyclic ligands have been synthesized. Structural characterization of the complexes is based on NMR spectroscopy, X-ray diffraction analysis, and differential scanning calorimetry. In addition, the catalytic activity of the complexes in the Suzuki–Miyaura cross-coupling of arylboronic acids and aryl halides has been tested.

The acyclic 4,9-bis(4-tolylsulfonyl)-4,9-diazadodeca-1,11dien-6-yne (1) and 4,9-bis(4-tolylsulfonyl)-4,9-diazatrideca-1,(E)-6-dien-11-yne (2), which differ in the sequence of the two ene and one yne functions in the chain, have been reacted with 1 and 2 equiv of Ni(cod) 2 . The reaction with 1 equiv of Ni(cod) 2 affords the mononuclear trigonalplanar nickel(0) complexes 3 and 5. These react with a further 1 equiv of Ni(cod) 2 by addition of a Ni(cod) entity to give the dinuclear derivatives 4 and 6. While 3 forms a mixture of isomers C 2 -3 and C s -3 in solution, C 2 -3 is exclusively present in the crystal, where it is packed in parallel columns. Complex 6 crystallizes as a spherulite. Complexes 3−6 have been characterized by NMR and single-crystal X-ray structure analysis, and a detailed conformational analysis is given.

A variety of new nitrogen-containing 15-membered triacetylenic macrocycles with one or two alkyl substituents in a propargylic position have been efficiently synthesized and completely characterized. These macrocyclic systems undergo [2 + 2 + 2] cycloaddition reactions, leading to the corresponding fused tetracycles with a benzene core on treatment with Wilkinson’s catalyst, [RhCl­(PPh3)3]. The effects of alkyl chains have been evaluated on both the efficiency of the reaction and the conformational and structural analysis of the reactants.

Chiral N-Phosphino Sulfinamide Ligands in Rhodium(I)-Catalyzed [2 + 2 + 2] Cycloaddition Reactions. -Cationic Rh-chiral N-phosphinosulfinamide complex is successfully applied in [2 + 2 + 2] cycloaddition reactions. Although only low to moderate enantioselectivity is achieved in intramolecular cycloaddition of enediynes (I) and (III), the PNSO ligand is suitable for further development due to its modular synthesis. -(BRUN, S.; PARERA, M.; PLA-QUINTANA, A.; ROGLANS*, A.; LEON, T.; ACHARD, T.; SOLA, J.; VERDAGUER, X.; RIERA, A.; Tetrahedron 66 (2010) 46, 9032-9040, http://dx.

Heteroaryl—aryl and heteroaryl—heteroaryl compounds are obtained through Suzuki—Miyaura cross‐coupling reactions between diazonium salts and potassium trifluoroborates using bis(acetonitrile)dichloropalladium(II) as the catalyst in water and in the absence of any additive, ligand or base.