2-(4-(Dimethylamino)phenyl)-3,3-difluoro-4,6-diphenyl-3,4-dihydro-1,2,4,5,3-tetrazaborinin-2-ium-3-ide

Reaction of 1-(4-(dimethylamino)phenyl)-3,5-diphenylformazane with boron trifluoride diethyl etherate (5 equiv) in the presence of triethylamine (3 equiv) in toluene medium gave “boratetrazine”—2-(4-(dimethylamino)phenyl)-3,3-difluoro-4,6-diphenyl-3,4-dihydro -1,2,4,5,3-tetrazaborinin-2-ium-3-ide in a 58% yield.

Synthesis of N-pentofuranosyl oxazolines and amides though the selective transformations of D-sugar acetonides

The method for synthesis of N-pentofuranosyl oxazolines was developed from the protected 1,2-O-acetonides of D-xylofuranose, -ribofuranose, and -arabinofuranose using boron trifluoride diethyl etherate, acetonitrile, and potassium hydrogen difluoride. A possible mechanism of the catalyzed reaction of acylated acetonides with acetonitrile in the presence of Lewis acid was considered in terms of the activation and cleavage of the 1,3-dioxalane part of the xylose derivative fol- lowed by the conversions of intermediates to α-isooxazoline. The hydrolysis reactions of N-α-glycosyl oxazolines were stud- ied in the acidic and neutral conditions. N-α-xylofuranosyl acetamide derivatives were prepared in high yields as a result of selective hydrolysis of protected α-xylofuranosyl isooxazolines in the neutral conditions.

The Different Outcomes of Electrochemical Copolymerisation: 3-Hexylthiophene with Indole, Carbazole or Fluorene

Electrochemical polymerisation is reported to be a method for readily producing copolymers of various conjugated molecules. We employed this method for mixtures of indole, carbazole or fluorene with 3-hexylthiophene (HT), in order to obtain their soluble copolymers. Although polymer films were obtained, infrared (IR) and Raman investigations showed that instead of the expected linear copolymers, polyindole and polycarbazole N-substituted with HT, as well as a poly(3-hexylthiophene) (PHT)/polyfluorene blend were produced instead. Boron trifluoride diethyl etherate was also used in an attempt to promote copolymerisation, but the produced deposits were found to be highly degraded.

Functionalized BODIPY Derivatives as Potential Fluorescent Labels

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives 1 and 2 were obtained with 16% and 33% yield by a two-step reaction: condensation of a pyrrole with the corresponding aldehyde followed by oxidation with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in the presence of boron trifluoride diethyl etherate (BF3OEt2). The two compounds were characterized by the usual spectroscopic techniques and a detailed photophysical study was undertaken. The compounds exhibited intense absorption bands at 502 nm and 497 nm, respectively. Emission studies of the compounds 1 and 2 showed emission bands with maximum wavelength at 518 nm and 519 nm, respectively.