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).

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.

Cytotoxic effect of amide derivatives of trifluoromethionine against the enteric protozoan parasite Entamoeba histolytica.

Amoebiasis, caused by infection with the enteric protist Entamoeba histolytica, is one of the major parasitic diseases. Although metronidazole and its derivatives are currently employed in therapy, the paucity of effective drugs and potential clinical resistance necessitate the development of a novel drug. Trifluoromethionine (TFM) is a promising lead compound for antiamoebic drugs.

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.

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.

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 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.

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.

Catalytic and highly enantioselective reactions of alpha-sulfonyl carbanions with chiral bis(oxazoline)s.

The enantioselective reactions of lithiated benzyl trifluoromethyl sulfones with a substoichiometric amount of a bis(oxazoline) and various aldehydes is disclosed. The products were formed with excellent diastereo- and enantioselectivities. Fluorination of the sulfone with N-fluorobenzenesulfonimide and a stoichiometric amount of a bis(oxazoline) gave products with extremely high enantioselectivities (up to 99% ee; ee=enantiomeric excess).

Enzymatic resolution and evaluation of enantiomers of cis-5'-hydroxythalidomide.

The straightforward synthesis of both enantiomers of cis-5'-hydroxythalidomide, a major metabolite of thalidomide, has been accomplished by enzymatic kinetic resolution of a racemic substrate catalyzed by Pseudomonas stutzeri lipase TL. cis-5'-Hydroxythalidomide shows resistance to racemization (and epimerization) at physiological pH. A tube formation assay to assess the ability to inhibit angiogenesis revealed that cis-5'-hydroxythalidomides are inactive.

Enantioselective C--C bond formation to sulfonylimines through use of the 2-pyridinesulfonyl group as a novel stereocontroller.

Enantioselective C--C bond formation to 2-pyridinesulfonylimines afforded products with good enantioselectivity. Dynamic induction of chirality on the sulfur by coordination of a chiral Lewis acid to the pyridine nitrogen and one of the prochiral sulfonyl oxygens induces enantioselectivity. Since the 2-pyridinesulfonyl group can easily be removed after the reaction, it acts not only as an activating group but also as an efficient stereocontroller.

Highly enantioselective reactions of configurationally labile epimeric diamine complexes of lithiated S-benzyl thiocarbamates.

Substitution reactions that employ primary-carbamoyl-protected arylmethanethiols are described. The enantiodetermining step was found to occur in the post-deprotonation step as a dynamic thermodynamic resolution with a chiral bis(oxazoline) ligand. The configurationally labile lithium complexes were trapped with various electrophiles to yield different substitution products in good to excellent yields and enantiomeric excesses.