The high response organic ultraviolet photodetectors based on 2-TNATA as donor

Organic ultraviolet photodetectors (OUV-PDs) were fabricated utilizing 2-TNATA as an electron donor with Bphen and TPBi as electron acceptors. A high sensitivity of OUV-PDs to UV light was obtained in the range of 300–420 nm. The optimized OUV-PDs composed of Bphen as the acceptor offered a photocurrent density up to 336 µA/cm² at ?8 V with 365 nm UV light at a power of 1.2 mW/cm². The high response is attributed to the excellent electron transport ability of Bphen and the matched energy level between 2-TNATA and Bphen.     

Practical and Scalable Synthesis of Ethyl (R)-Piperidine-3-acetate

A practical and scalable synthesis of ethyl (R)-piperidine-3-acetate was achieved from commercially available 3-pyridylacetic acid in 76% overall yield. The practical synthesis was demonstrated on 100-g scale. One-pot reductive N-ethylation of the pyridinium salt with acetonitrile gave an N-ethyl piperidine derivative.     

β-cyclodextrin Sensitized Spectrofluorimetry for the Determination of Abiraterone Acetate and Abiraterone

A novel spectrofluorimetric method to determine abiraterone acetate and its active metabolite, abiraterone was developed, based on the fact that fluorescence intensity of abiraterone acetate and abiraterone could be enhanced in β-cyclodextrin (β-CD) due to the formation of the inclusion complex. The inclusion interaction of β-CD and abiraterone acetate and the β-cyclodextrin sensitized spectrofluorimetry was examined. The various factors influencing fluorescence were discussed in details. The results showed that under the optimized conditions, the linear range of calibration curve for the determination of biraterone acetate and abiraterone was 0.20?~?6.0 μg/mL, and the detection limit (LOD) was 6.8 (r?=?0.997) or 6.6 ng/mL (r?=?0.996), respectively. No interference was observed from common co-existing substances or pharmaceutical excipient. The method was successfully applied to the analysis of abiraterone acetate in pharmaceutical formulation and abiraterone in human serum/urine.     

Theoretical study on the origin of enantioselectivity in the primary amine–Brønsted acid catalyzed epoxidation of cyclic enones

Computational studies to determine the origin of enantioselectivity in the (1R,2R)-1,2-diphenylethane-1,2-diamine (DEPN)–Brønsted acid catalyzed epoxidation of 2-cyclohexen-1-one have been performed using density functional theory. Transition states for conjugate addition and ring closure steps of the epoxidations catalyzed by three different catalyst systems were characterized. Our calculations show that the C_sp2H?O H-bond interaction between the benzene ring of the catalyst and H₂O is mainly responsible for the chiral discrimination observed. The Brønsted acid counterion plays a very important role in ensuring high enantioselectivity by improving the rigidity of the transition state structures to allow the efficient formation of the C_sp2H?O H-bond. Moreover, we explain why these two diamine catalysts (1S,2S)-DACH and (1R,2R)-DPEN display consistent enantioselectivities in the catalytic epoxidation of 2-cyclohexen-1-one when combining with three different cocatalysts; achiral TFA, and chiral (R)- and (S)-TRIP.     

TEMPO-Based Ionic Liquid with Temperature-Dependent Property and Application for Aerobic Oxidation of Alcohols

A novel temperature-dependent ionic liquid based on 2,2,6,6-tetramethylpiperidine-1-oxyl and polyethylene glycol 600 was developed and used in oxidation of alcohols. Various alcohols were oxidized into their corresponding aldehydes or ketones with good yield and selectivity. Owing to the temperature-dependent property of the catalyst, easy recovery was achieved by simple decantation.

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