Abstract:The ionic liquids, BMIM PF 6 or BMIM NTf 2 , are used successfully for the palladium-catalyzed cyclocarbonylation of 2-allylphenols and anilines, 2-vinylphenols, and 2-aminostyrenes. The reaction proceeds cleanly and efficiently to afford high yields of lactones or lactams with good or excellent selectivity for one isomer. The ionic liquid containing the palladium catalyst, and ligand, is recyclable in all cases.

Dihalodiphenylacetylenes are conveniently synthesized by a double elimination reaction of b-substituted sulfones which are readily obtained from halogen-substituted benzyl sulfone and benzaldehyde derivatives. Halogens can be incorporated at any desired positions in the diphenylacetylene skeleton simply by choosing the substitution position of the halogen on the aromatic rings of the starting compounds. The diphenylacetylenes with different halogen substituents thus obtained undergo sequential carboncarbon bond formations due to the different reactivities of the halogens. Thus, various moieties can be incorporated on the diphenylacetylene skeleton at whichever positions so that a variety of tailor-made phenylene-ethynylenes with regulated structure and composition could be designed.

The palladium-catalyzed cyclocarbonylation reaction of o-iodoanilines with allenes and CO in 1-butyl-3-methylimidazolium hexafluorophosphate afforded 3-methylene-2,3-dihydro-1H-quinolin-4-ones in moderate to excellent yields under a low pressure (5 atm) of CO. The ionic liquid, as the solvent and promoter, enhances the efficiency of the cyclocarbonylation reaction. The recyclability of the system of ionic liquid/catalyst/ligand was also demonstrated.

In order to realize high birefringence, acetylenes with long molecular size such as bis(phenyldiynyl)benzenes 1 and diphenylhexatriynes 4 are synthesized successfully on the basis of double elimination of the β-substituted sulfones which can be prepared easily by reaction of benzyl or propargyl sulfones with propynal derivatives.

The double elimination reaction of β-substituted sulfones offers a versatile strategy for synthesis of arylene ethynylene kits containing heteroaromatic rings. A sequence of aldol reaction between α-sulfonyl carbanion and aldehyde, trapping the resulting aldolate to give β-substituted sulfone, and double elimination of this intermediate can be integrated in one pot. This protocol allows thiophene, pyridine, and ferrocene units to be accommodated in phenylene ethynylene arrays.Key words: arylene–ethynylenes, heteroaromatic rings, ferrocene, double elimination, sulfones.

No abstract

Form Methylene-2,3-dihydro-1H-quinolin-4-ones. -The process offers a straightforward and efficient method to prepare various title quinolinones. The ionic liquid/catalyst/ligand system can be recovered and reused some times without significant loss of activity. -(YE, F.; ALPER*, H.; J. Org. Chem. 72 (2007) 9, 3218-3222; Cent. Catal. Res. Innov., Univ. Ottawa, Ottawa, Ont. K1N 6N5, Can.; Eng.) -Jannicke 36-130

The title compound, μ‐penta­cyclo­[26.4.0.09,14.017,22.025,30]­dotriaconta‐1,3,5,9,11,13,15,17,19,21,25,27,29,31‐tetradecaene‐7,24‐diyne‐bis­(tri­carbonyl­cobalt) di­chloro­methane solvate, [Co2(η2‐C32H20)(CO)6]·CH2Cl2, has been prepared by treatment of a de­hydro­benzoannulene with octa­carbonyldi­cobalt. This cobalt complex is chiral in the solid state and exhibits alternate arrays of P‐ and M‐conformations.