Flexible routes to thiophenes.

Three convergent routes to thiophenes are described, hinging on the radical addition of α-xanthyl ketones to ethyl vinyl sulfide or to vinyl pivalate. The latter route ultimately proved to be the most versatile and efficient (61-94%).

Antitumor trans-N-heterocyclic carbene-amine-Pt(II) complexes: synthesis of dinuclear species and exploratory investigations of DNA binding and cytotoxicity mechanisms.

A series of bimetallic [(NHC)PtX2]2(diamine) complexes have been prepared as a new chemotype for potential anticancer agents. These complexes display an uncommon set of structural features as far as they combine two bifunctional, trans-configured platinum centers. They display cytotoxic activities in the micromolar range on many cancerous cell lines and do not cross-react with cisplatin in A2780/DDP cell lines.

Enantioselective, transition metal catalyzed cycloisomerizations.

This review illustrates enantioselective transition-metal promoted skeletal rearrangements of polyunsaturated substrates possessing olefin, alkyne or allene functions. These processes are classified according to the number of carbon atoms involved in the cyclization, from (1C+1C) to (2C+2C+2C) or (2C+5C) cyclizations. Thus, for instance, (1C+1C) processes are typified notably by Alder-ene type reactions taking place mainly under palladium and rhodium catalysis, in the presence of chiral phosphorus ligands.

Platinum(II) catalysts for highly enantioselective 1,6-enyne cycloisomerizations. synthetic, structural, and catalytic studies.

A new family of cyclometalated (N-heterocyclic carbene)-Pt(II) complexes bearing monodentate phosphines as ancillary ligands has been designed for use as precatalysts in 1,6-enyne cycloisomerization reactions. Highly enantioselective skeletal rearrangements of allylpropargyl-tosylamide derivatives have been developed by using (S)-Ph-Binepine as the chiral auxiliary. Enantiomeric excesses up to 97% have been obtained.