Theoretical study on the ionization of aniline in aqueous solutions

The ionization and excitation processes of aniline in aqueous solutions are investigated by the method of RISM-SCF-SEDD (reference interaction site model self-consistent field with the spatial electron density distribution). Four different models are employed to characterize the response of the solvation upon the ionization and excitation. A simple treatment for estimation of the spectral width is also proposed

Asymmetric Introduction of Nucleophiles to the 2-Position of Pyrrolidine Ring through N-Acylpyrrolidinium Ion

Asymmetric carbon-carbon bond-forming reaction at the 2-position of a pyrrolidine ring was achieved. The reaction involved a chiral Ti(IV) catalyzed coupling between 1-methoxycarboyl-2-methoxypyrrolidine and silyl enol ethers to afford 2-substituted pyrrolidines with up to 53 % ee

Memory of Chirality in the Electrochemical Oxidation of N-o-Phenylbenzoylated Prolinols

Memory of chirality in electrochemical carbon-carbon bond cleavage of N-o-phenylbenzoylated (S)-prolinol derivatives was observed. Substituents of the α-position affected the ee of the products. The reaction of α,α-diarylated (S)-prolinol derivatives proceeded smoothly to afford optically active α-methoxylated pyrrolidine with up to 73% ee

Panretinal Photocoagulation Using Short-Pulse Laser Induces Less Inflammation and Macular Thickening in Patients with Diabetic Retinopathy

We compared the effect of panretinal photocoagulation (PRP) using short-pulse laser (SPL) and conventional laser, regardless of the number of spots, in terms of their effect on the progression of diabetic macular edema (DME) and anterior flare intensity (AFI) in patients with high-risk nonproliferative diabetic retinopathy (non-PDR). Forty-two eyes of 42 patients were subjected to PRP using the conventional argon laser (Conv group) or SPL (SPL group). CRT and AFI levels in the SPL group were significantly lower than those in the Conv group (CRT at 4, 6, and 10 weeks; AFI at 6, 10, and 18 weeks). Eyes of rabbits were photocoagulated using conventional laser with 500 spots (Conv 500s), SPL with 500 spots (SPL 500s), or 1000 spots (SPL 1000s). Vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) levels in vitreous humor were measured using an immunoassay. Compared to conventional laser, VEGF, IL-6, and MCP-1 levels were significantly lower in the SPL 1000s and SPL 500s groups. In patients with high-risk non-PDR, SPL has a greater preventive effect on the progression of DME and AFI and produces less inflammatory cytokines than conventional lasers

Stereoselective synthesis of 3-deoxy-piperidine iminosugars from l-lysine

A new method using electrochemical oxidation and/or OsO4 oxidation has been used for the stereoselective synthesis of 2,3,6-trihydroxylated (5S)-piperidine derivatives. The electrochemical method was successively used for the conversion of N-protected piperidines to N-protected 1-methoxypiperidines and for the conversion of 2,3-didehydro-1-methoxypiperidine derivatives to 2,3-trans-1,2,3-triacetoxypiperidine derivatives. These triacetates were easily transformed into (2S,3S)-6-triacetoxy-(5S)-methylpiperidine and (2R,3R)-6-triacetoxy-(5S)-methylpiperidine. In addition, the 2,3-cis-dihydroxylation of 2,3-didehydro-1-methoxypiperidine derivatives with OsO4 afforded (2R,3S)-6-triacetoxy-(5S)-methylpiperidine and (2S,3R)-6-triacetoxy-(5S)-methylpiperidine

Copper complex catalyzed asymmetric monosulfonylation of meso-vic-diols

Asymmetric desymmetrization of meso-vic-diols was performed by tosylation in the presence of copper(II) triflate and (R,R)-Ph-BOX as a catalyst. The method was successfully applied to asymmetric desymmetrization of cyclic and acyclic meso-vic-diols in high enantioselectivity with up to >99% ee

Catalytic monoalkylation of 1,2-diols

A catalytic monoalkylation of 1,2-diols by using a weak base has been developed. Copper(II) dichloride and boronic acids are effective catalysts for activating 1,2-diols in the presence of potassium carbonate as a base. Various 1,2-diols were selectively monoalkylated with allyl-, benzyl- and alkyl- halides in DMF by choosing a suitable catalyst for each 1,2-diols

New organic activators for the enantioselective reduction of aromatic imines with trichlorosilane

N-Picolinoyl-(2S)-(diphenylhydroxymethyl)pyrrolidine was found to work as an organic activator in the reduction of aromatic imines to the corresponding amines by Cl3SiH. The highest selectivity was 80% ee. These are the first data showing that N-formyl group is not always essential as N-protecting group of pyrrolidine derivatives for the reduction of imines by Cl3SiH