Efficient synthesis of new fluorinated building blocks by means of hydroformylation.

Hydroformylation of fluorinated alkenes is an efficient method for the preparation of fluorinated functionalized building blocks for the synthesis of biologically active target structures. In this article we summarize known hydroformylation reactions of fluorinated olefins and we add new results from our research groups. Particular attention is paid to the remarkable influence of organofluorine substituents on catalyst activity, regio- and stereoselectivity of the hydroformylation reaction.

Tandem decarboxylative hydroformylation-hydrogenation reaction of α,ß-unsaturated carboxylic acids toward aliphatic alcohols under mild conditions employing a supramolecular catalyst system.

A new atom economic catalytic method for a highly chemoselective reduction of α,ß-unsaturated carboxylic acids to the corresponding saturated alcohols under mild reaction conditions, compatible with a wide range reactive functional groups, is reported. The new methodology consists of a novel tandem decarboxylative hydroformylation/aldehyde reduction sequence employing a unique supramolecular catalyst system.

Silver-catalyzed cycloisomerization of 1,n-allenynamides.

A variety of allenynamides can undergo cycloisomerization reactions in the presence of silver triflate thus leading to the formation of N-containing heterocycles incorporating cross-conjugated trienes. Access to new dienic 4-piperidinone and azepane motifs was achieved. An extension to one-pot tandem sequences involving silver-catalyzed cycloisomerization/Diels-Alder reaction was also examined.

Diphosphine sulfides derived from 2,2'-biphosphole: novel chiral S,S ligands for palladium-catalyzed asymmetric allylic substitution.

Diphosphine sulfides derived from 2,2'-biphosphole have been efficiently synthesized in an enantiomerically pure form by a four step synthetic sequence. These S,S-ligands were used for the first time in Pd-catalyzed asymmetric allylic alkylation. Good yields and enantiomeric excess up to 73% were obtained.

New enantiopure palladium(II) complexes from a stereodynamic 2,2'-biphosphole ligand.

Two enantiopure palladium(II) complexes, viz. [1,1'-(butane-1,3-diyl)-3,3',4,4'-tetramethyl-5,5'-diphenyl-2,2'-biphosphole]dichloridopalladium(II) dichloromethane solvate [systematic name: dichlorido(1,2,5,10,11-pentamethyl-3,9-diphenylperhydrodicyclopenta[a,c][1,4]diphosphepine-kappa(2)P,P')palladium(II) dichloromethane solvate], [PdCl2(C28H30P2)] x CH2Cl2, have been synthesized from stereodynamic diphosphines derived from 2,2'-biphosphole through a metal kinetic dynamic resolution. In both structures, the coordination around the metal atom is square planar, with a cis arrangement of the ligands that drastically reduces the dihedral angle between the two phosphole rings compared with the free ligand. The structural determination of both enantiomers unambiguously establishes the absolute configuration of both central and axial elements of chirality of the 2,2'-biphosphole framework and indicates that the original carbon chirality of the backbone controls the chiralities of the 2,2'-biphosphole framework.

Dichlorido[(S,R(S))-1-diphenylphosphino-2-(ethylsulfanylmethyl)ferrocene]palladium(II).

The reaction of enantiomerically pure planar chiral ferrocene phosphine thioether with bis(acetonitrile)dichloridopalladium yields the title square-planar mononuclear palladium complex as an enantiomerically pure single diastereoisomer, [PdFe(C5H5)(C20H20PS)Cl2]. The planar chirality of the ligand is retained in the complex and fully controls the central chirality on the S atom. The absolute configuration, viz. S for the planar chirality and R for the S atom, is unequivocally determined by refinement of the Flack parameter.