Synthetic applications of o- and p-halobenzyl sulfones as zwitterionic synthons: preparation of ortho-substituted cinnamates and biarylacetic acids

The synthetic applications of o-halobenzyl and p-halobenzyl sulfones as precursors of 1,3- and 1,5-zwitterionic synthons, respectively, are described. Their alpha-sulfonyl carbanions, generated by means of the phosphazene base P2-Et or BuLi or K2CO3 under PTC conditions, reacted with different electrophiles such as alkyl halides, aldehydes, and electrophilic olefins. Palladium-catalyzed cross-coupling processes such as Heck, Suzuki, and Sonogashira reactions can be efficiently performed at the halogen atom. These two sequential functionalization processes are applied to the synthesis of ortho-substituted cinnamates and pharmaceuticals belonging to the family of p-biarylacetic acids such as 4-biphenylacetic acid, namoxyrate, xenyhexenic acid, and biphenylpropionic acid.     

Productive trapping of NAD-type radicals. Non-biomimetic reduction of pyridinium salts

One-electron reduction of pyridinium salts (NAD+ analogues) generates dihydropyridyl radicals which may then be engaged in radical addition processes to regioselectively form gamma-substituted dihydropyridines.     

Synthesis and characterization of [Cu(Me2oxpn)Ni(NO2)(tmen)](ClO4): a single ferrimagnetic dinuclear CuII-NiII complex acting as weak molecule-based magnet

The new heterodinuclear complex [Cu(Me2oxpn)Ni(NO2)(tmen)](ClO4), that exhibits strong antiferromagnetic intramolecular coupling between CuII and NiII ions (ferrimagnetic behavior), shows ferromagnetic ordering at low temperature, due likely to a small canting phenomenon; it is one of the very few compounds made from isolated molecules that lead to cooperative magnetic behavior.     

Minimalist peptidomimetic cyclophanes as strong organogelators

L-Valine containing cyclophanes have been shown to gelate organic solvents leading to soft materials with a clear expression of their chirality at the supramolecular level.