Synthesis and configurational stability of (S)- and (R)-deuteriothalidomides.

3'-Deuteriothalidomide was synthesized and found to be configurationally five times more stable than thalidomide toward racemization at physiological pH.

Poly[(3-hexylthiophene)-block-(3-semifluoroalkylthiophene)] for polymer solar cells.

We report the synthesis of poly[(3-hexylthiophene)-block-(3-(4,4,5,5,6,6,7,7,7-nonafluoroheptyl)thiophene)], P(3HT-b-3SFT), carried out by the Grignard Metathesis Method (GRIM). The copolymers composition was determined by (1)H and (19)F NMR spectroscopies, and gel permeation chromatography (GPC). The thin films of P(3HT-b-3SFT) were investigated by ultraviolet-visible absorption spectroscopy and atomic force microscopy (AFM). We also fabricated bulk-hetero junction (BHJ) solar cells based on blends of P(3HT-b-3SFT) and [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM). Although the composition ratio of P3SFT in P(3HT-b-3SFT) was low, the influence of P3SFT on the morphology and properties of solar cells was significant. The annealing process for the BHJ solar cells induced the formation of large domains and led to poor solar cell performance. The BHJ solar cells, based on PCBM and P(3HT-b-3SFT), prepared by the non-annealing process, had a maximum power conversion efficiency of 0.84% under 100 mW/cm(2) (AM 1.5 solar illumination) in air.

Catalytic enantioselective hydrophosphonylation of ketimines using cinchona alkaloids.

Organocatalytic enantioselective hydrophosphonylation of ketimines using cinchona alkaloids and Na(2)CO(3) afforded products with high enantioselectivity. Both enantiomers of alpha-amino phosphonates can be prepared by using pseudoenantiomeric cinchona alkaloids. The catalyst loading of cinchona alkaloids can be reduced to 0.5 mol % without a significant loss of enantioselectivity.

Synthesis, configurational stability and stereochemical biological evaluations of (S)- and (R)-5-hydroxythalidomides.

The first asymmetric synthesis of (S)- and (R)-5-hydroxythalidomides, one of thalidomide's major metabolites, was achieved using HMDS/ZnBr(2)-induced imidation as a key reaction. 5-Hydroxythalidomide was found to be configurationally more stable than thalidomide at physiological pH. Stereochemical biological effects of thalidomide and 5-hydroxythalidomide on anti-angiogenesis and antitumor activities were also investigated using racemic and pure enantiomers.

Synthesis of trifluoroethoxy-coated binuclear phthalocyanines with click spacers and investigation of their clamshell behaviour.

We disclose here the synthesis of a novel trifluoroethoxy-coated binuclear Pc which is the first example of a never-closing clamshell Pc.

Enantioselective electrophilic trifluoromethylation of beta-keto esters with Umemoto reagents induced by chiral nonracemic guanidines.

Chiral nonracemic guanidines act as Brønsted bases to generate guanidinium enolates for the enantioselective electrophilic trifluoromethylation of beta-keto esters by means of S-(trifluoromethyl)dibenzothiophenium tetrafluoroborate (Umemoto reagent) with good enantioselectivity of 60-70% range. Despite the fact that the ees are still improvable, the model reported in this work could spark the imagination of chemists to design new chiral bases to improve the stereochemical outcome.

New diarylmethanofullerene derivatives and their properties for organic thin-film solar cells.

A number of diarylmethanofullerene derivatives were synthesized. The cyclopropane ring of the derivatives has two aryl groups substituted with electron-withdrawing and -donating groups, the latter with long alkyl chains to improve solubility in organic solvents, an important property in processing cells. First reduction potentials of most derivatives were less negative than that of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which is possibly ascribed to their electron-withdrawing nature. Organic thin-film photovoltaic cells fabricated with poly(3-hexylthiophene) (P3HT) as the electron-donor and diarylmethanofullerene derivatives as the electron-acceptor material were examined. The {(methoxycarbonyl)phenyl[bis(octyloxy)phenyl]methano}fullerene showed power conversion efficiency as high as PCBM, but had higher solubility in a variety of organic solvents than PCBM. The V(oc) value was higher than that of PCBM, which is derived from the electron-donating (octyloxy)phenyl group, possibly raising the LUMO level. Photovoltaic effects of the devices fabricated with the derivatives having some electron-withdrawing groups were also examined.

Synthesis and properties of trifluoroethoxy-coated binuclear phthalocyanine.

A genuine example of non-aggregated highly fluorescent binuclear phthalocyanines is reported; spectroscopic studies and computations revealed that the two halves of trifluoroethoxy-coated binuclear phthalocyanine are rotated in the same directions so as to contact each other as much as possible.

Synthesis of covalently linked binuclear clamshell phthalocyanine by double-click reaction.

A novel covalently linked binuclear phthalocyanine 1 was synthesized by the "double-click" reaction. The UV-vis and fluorescence spectra and electrochemistry revealed that the geometry of 1 is a closed clamshell conformation in which a strong electronic interaction is observed between the two Pc moieties.

DBFOX-Ph/metal complexes: evaluation as catalysts for enantioselective fluorination of 3-(2-arylacetyl)-2-thiazolidinones.

We examined the catalytic enantioselective fluorination of 3-(2-arylacetyl)-2-thiazolidinones 1 with N-fluorobenzenesulfonimide (NFSI) by DBFOX-Ph/metal complexes under a variety of conditions. After optimization of the metal salts, solvents and additives, we found that the fluoro-2-thiazolidinones 2 were obtained in good to high yields with moderate to good enantioselectivities (up to 78% ee) when the reaction was carried out in the presence of DBFOX-Ph (11 mol%), Ni(ClO(4))(2).6H(2)O (10 mol%) and 2,6-lutidine (0 or 1.0 equiv) in CH(2)Cl(2).

Cinchona alkaloids/TMAF combination-catalyzed nucleophilic enantioselective trifluoromethylation of aryl ketones.

The catalytic, nucleophilic enantioselective trifluoromethylation reaction of both acyclic and cyclic aryl ketones using the Ruppert-Prakash reagent is now at hand, with an operationally simple procedure, based on the combination of ammonium bromide of cinchona alkaloids with TMAF. The procedure is reliable and general. Trifluoromethyl-substituted tetrasubstituted aryl alcohols have been synthesized in up to 94% ee.

Lewis acid-catalyzed tri- and difluoromethylation reactions of aldehydes.

The first Lewis acid-catalyzed trifluoromethylation reactions of aldehydes with Me3SiCF3 under TiF4/DMF, Ti(O iPr)4/DMF and Cu(OAc)2/dppp/toluene conditions are described. We have successfully applied this methodology to the difluoromethylation of aldehydes using Me3SiCF2SePh, Me3SiCF2P(O)OEt2 and Me3SiCF2SPh.