Basic study for acyl chitosan isothiocyanates synthesis by model experiments using glucosamine derivatives.

Affecting factors to the acyl chitosan isothiocyanate synthesis by N-phenylthiocarbamoylation and the following acylation was investigated using octyl 2-amino-2-deoxy-β-D-glucopyranoside as a model compound. It was found from the acetylation of N-phenylthiocarbamoyl glucosamine derivative with acetic anhydride/pyridine that the glucosamine isothiocyanate was formed via N,N-(acetyl)phenylthiocarbamoyl glucosamine derivative and the conversion of N,N-(acetyl)phenylthiocarbamoyl glucosamine derivative to the glucosamine isothiocyanate proceeded mainly by thermal degradation of N,N-(acetyl)phenylthiocarbamoyl groups. The reaction temperature was an important factor to the isothiocyanate synthesis.

Preparation and electro-optical properties of triphenylamine-bound chitosan derivative.

3,6-Di-O-hexanoyl-N-[4-(N,N-diphenylamino)-1-phenyl] thiocarbamoyl chitosan was prepared from 3,6-di-O-hexanoyl chitosan isothiocyanate in a 78% yield, and spin-coated films of the chitosan derivative and tris(2-phenylpyridine)iridium (Ir(ppy)) were fabricated. Ultraviolet-visible absorption spectra and photoluminescence spectra of the films indicated efficient Förster energy transfer from the chitosan derivative to the Ir(ppy). An electroluminescent device using both compounds emitted green luminescence when voltage was applied.

Preparation of a Near-Infrared Ray Absorption Film from N-Phenylthiocarbamoyl Chitosan Derivative.

We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (3a). This result suggested that some of the N,N-(decanoyl)phenylthiocarmbamoyl groups had been converted to isothiocyanate groups during the decanoylation process. The subsequent reaction of compound 3b with aniline gave N,N-(decanoyl)phenylthiocarbamoyl/N-phenylthiocarbamoyl chitosan decanoate (4) in high yield.

Facile synthesis of acyl chitosan isothiocyanates and their application to porphyrin-appended chitosan derivative.

Chitosan (1) was reacted with phenylisothiocyanate in 5% AcOH/H2O to give N-phenylthiocarbamoyl chitosan (2) with a degree of substitution (DS) of N-phenylthiocarbamoyl groups of 0.86 in 87.1% yield.

Tandem Staudinger/aza-Wittig reaction of 6-azido-6-deoxycellulose derivative.

The tandem Staudinger/aza-Wittig reaction of the 6-azido-6-deoxycellulose derivative (2) with triphenylphosphine and carbon disulfide afforded the corresponding 6-isothiocyanato-6-deoxycellulose derivative (3) in 47.3% yield. Compound 3 was further reacted with 4'-aminobenzo-15-crown ether to afford the crown ether-containing 6-N-thioureido-6-deoxycellulose derivative (4) in 70.