We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

Residual heteronuclear dipolar couplings obtained from partially oriented protein samples can provide unique NMR constraints for protein structure determination. However, partial orientation of protein samples also causes severe 1H line broadening resulting from residual 1H-1H dipolar couplings. In this communication we show that band-selective 1H homonuclear decoupling during data acquisition ...

An unexpected and interesting intramolecular side reaction occurred during the attempted synthesis of glycosyl cyanides upon treatment of 1-O-acetyl-3-azido-3-deoxyallose derivatives with TMSCN and different Lewis acids. Exo-1,2-O-cyanoalkylidene derivatives formed by neighboring group participation and attack of cyanide underwent, after Lewis-acid mediated isomerization to the endo-isomer, int...

It is known that ammonium azides are both effective and convenient azidation agents, which are widely used in the syntheses of tetrazoles in media of aprotic dipolar solvents. However, until the present time, information about using these reagents for the synthesis of the 1,2,3-triazoles has been absent. In this case, alkali metal azides as well as trimethylsilyzide are the best known azidation...

The ongoing study is a Ugi-azide four-component reaction for the synthesis of 1,5-disubstituted tetrazole(1,5-DST), which involves an aldehyde, different amines, isocyanides, and as azide’s source Trimethylsilylazide (TMSN3), in water solvent using catalyst tetradecyltrimethylammonium bromide (TTAB) with load (10% mole), provides hydrophobic micellar site. This approach step toward green chemis...

Syntheses of N,N'-phenyltetrazole podands link with aliphatic chains containing oxygen, nitrogen and sulphur atoms, are described. The complexing properties of these compounds towards metal cations (Fe2+, Cu2+, Zn2+, Co2+, Ni2+) were investigated by absorption and infrared spectroscopy. The UV-Vis titrations were performed to estimate the stability constant values of the respective complexes wi...

Nitrogen-rich polymers were synthesized by radical polymerization using the reaction of 5aminotetrazole with methacryloyl chloride and acryloyl chloride, respectively. The nitrogen content of poly(methacrylamidotetrazole) and poly(acrylamidotetrazole), as well as the energetic character of these compounds was increased by nitration of the amido moiety. The products remained however insensitive ...

We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52-57, 2006]. First, we demonstrate that 1H indirect detection improves the...

A new glutarimide antibiotic named actiketal was isolated from the culture fluid of the epiderstatin-producing streptomycete, Streptomyces pulveraceus subsp. epiderstagenes. The IC50 of the antibiotic for inhibition of the incorporation of [3H]thymidine into epidermal growth factor-stimulated Balb/MK cells was 14.5 microM. The structure of this compound was determined by 1H and 13C NMR spectros...

One novel triterpene cycloartane-type, named hirtinone (1), six protolimonoids - nilocitin (2), dihydronilocitin B (3), melianone epimers (4) and (5), piscidinol A (6) and melianone lactone (7), one tertranortriterpenoid, hirtin (8), and one sesquiterpene, spathulenol (9), were identified in the fruits of Trichilia hirta. The structures were established by 1D and 2D NMR (1H and 13C-NMR, DEPTQ, ...