Degradation of benzotrifluoride via the dioxygenase pathway in Rhodococcus sp. 065240.

We previously isolated Rhodococcus sp. 065240, which catalyzes the defluorination of benzotrifluoride (BTF). In order to investigate the mechanism of this degradation of BTF, we performed proteomic analysis of cells grown with or without BTF.

Synthesis and antibacterial activity of alaremycin derivatives for the porphobilinogen synthase.

The preparation and the antibacterial activity of alaremycin derivatives such as their CF(3)-derivatives and (R)- and (S)-4-oxo-5-acetylaminohexanoic acid for the porphobilinogen synthase (PBGS), were described. The IC(50) values of the antibacterial activity of the prepared materials for the inhibitor of PBGS, were determined using PBGS assay.

Antibacterial activities of imidazolium, pyrrolidinium and piperidinium salts.

The antibacterial activity of various types of imidazolium, pyrrolidinium and piperidinium salts with both propargyl group and alkyl and/or silylalkyl chains of different lengths, are described. Especially, the MIC (μg/ml) of prepared each compound for Escherichia coli and other several bacteria was determined.

Realization of anti-SN2' selective allylation of 4-cyclopentene-1,3-diol monoester with aryl- and alkenyl-zinc reagents.

Anti-SN2' mode of allylation of the monoester of 4-cyclopentene-1,3-diol with aryl and alkenyl anions was achieved, for the first time, with the MeOCH2CO2- group as a leaving group to which R-ZnBr and CuCl (as a catalyst) were best fitted. The aryl groups successfully installed were Ph, o- and p-MeC6H4, o-MOMOC6H4, o-MeOC6H4, and p-F-C6H4, while cis and trans alkenyl groups were attached with retention of the olefinic stereochemistries.

Structure-activity relationship study of the bacterial actin-like protein MreB inhibitors: effects of substitution of benzyl group in S-benzylisothiourea.

We comprehensively investigated the effects of substitution of the benzyl group in S-benzylisothiourea derivatives on antibacterial activity, because we found previously that some substitutions enhanced it. A 2,4-Cl2-derivative was found to be the most effective compound, it was stronger than the original one in Gram-negative rod shaped-bacteria such as Escherichia coli and Salmonella typhimurium.

Synthesis of trifluoro- or difluoromethylated olefins by regio- and stereocontrolled S(N)2' reactions of gem-difluorinated vinyloxiranes.

This paper presents a highly stereoselective synthesis of trifluoro- or difluoromethylated olefins via an S(N)2' type fluorination or reductions of gem-difluorinated vinyloxiranes. Their fluorination with HF-Py furnished trifluoromethylated allylic alcohols with exclusive E selectivity. On the other hand, their reduction with DIBAL-H afforded difluoromethylated E-allylic alcohols predominantly, whereas the corresponding Z isomers were formed exclusively by treatment with BH3.

In situ generation of 3,3,3-trifluoropropanal and its use for carbon-carbon bond-forming reactions.

The DIBAL reduction of 2-phenylethyl 3,3,3-trifluoro-2-methylpropionate 2 at -78 degrees C afforded the aluminum acetal 3, and this intermediate, on worming up to 0 degrees C, was found to slowly decompose into the corresponding aldehyde 4, which smoothly reacted with appropriate nucleophiles in a one-pot manner in good to excellent yields with up to 93% diastereoselectivity.

Regio- and stereoselective reactions of gem-difluorinated vinyloxiranes with heteronucleophiles.

[Reaction: see text]. Regio- and stereoselectivity in reactions of gem-difluorinated vinyloxiranes with heteronucleophiles were successfully controlled. Halogen atoms were introduced regioselectively at the allylic epoxide carbon with an inversion in stereochemistry using MgBr2*Et2O or Li2CuCl4 to produce anti-vic-halohydrine.

Stereocontrolled synthesis of beta-difluoromethylated materials.

Investigation of synthetic routes for regio- and stereocontrolled fluorinated materials with a difluoromethyl group, using ethyl bromodifluoroacetate as a starting material, is described. In particular, (E)-difluoromethylated trisubstituted olefins were prepared via the proton migration reaction catalyzed by using fluoride anion. Further, optically active beta-difluoromethyl esters were obtained by the enzymatic resolution.

Construction of optically active CF3-containing quaternary carbon centers via stereospecific S(N)2' reaction.

[reaction: see text] Phosphates from 3-substituted 4,4,4-trifluorobut-2-en-1-ols were found to be effective for construction of CF3-containing quaternary carbon centers by way of Cu(I)-catalyzed Grignard reactions in the presence of catalytic amounts of CuCN and trimethylsilyl chloride (TMSCl) in an anti S(N)2' manner.

Structure-activity relationship of S-benzylisothiourea derivatives to induce spherical cells in Escherichia coli.

We have previously reported that a novel S-benzylisothiourea derivative, S-(3,4-dichlorobenzyl)isothiourea, tentatively named A22, induced spherical cells in Escherichia coli. To elucidate the structural element(s) required for inducing these spherical cells, the biological activity of S-benzylisothiourea derivatives and related compounds toward E. coli cells was investigated.

Preparation and regioselective SN2' reaction of novel gem-difluorinated vinyloxiranes with RLi.

A series of hitherto unknown 3,4-epoxy-1,1-difluorobutenes were prepared from the readily accessible alpha,beta-epoxy ketones and these compounds were found to undergo regioselective S(N)2' reactions with hard RLi nucleophiles occurring at the highly positively charged terminal fluorine-possessing sp(2) carbon atom in quite sharp contrast to the cases of the corresponding nonfluorinated vinyloxiranes which only attained a low level of regioselectivity. Addition of HMPA substantially improved the products' olefinic stereoselectivity. Theoretical calculations were used to qualitatively explore the nature of selectivity in these reactions.

Electronically promoted Payne rearrangement of 3-CF3-2,3-epoxyalcohols.

[reaction: see text] Smooth and selective Payne rearrangement was achieved for the above types of epoxyalcohols with a CF(3) group so as to form thermodynamically more stable alkoxides, where the strongly electron-withdrawing nature of this moiety played a significantly important role and was proved to overcome increased steric instability of epoxides from syn-E to anti-Z isomers.

Preparation and regioselective reactions of novel gem-difluorinated vinyloxiranes with some organometallic reagents.

Hitherto unknown, relatively labile gem-difluorinated vinyloxiranes were prepared by difluoro-Wittig reactions with alpha,beta-epoxyketones; for these vinyloxiranes alkyl groups were delivered at the fluorine-attached terminal carbon atom in an SN2' manner by RLi, while Me3Al and MeMgBr-CuCl (3: 1) introduced the Me group at the allylic epoxy carbon with retention and inversion of the original stereochemistry, respectively.

Synthetic Applications of the Carbanion with a Fluoroalkyl Group Generated by Palladium(0) Catalyst under Neutral Conditions.

The generation and synthetic application of stable carbanions situated in the beta position from fluorine atom(s) are described. Palladium(0)-catalyzed allylation reactions under neutral conditions proceeded smoothly in the system where a methylene group is activated by fluoroalkyl and carbonyl groups. In the above systems, the 2,2,2-trifluoroethyl moiety has been introduced onto the allylic position without the release of fluoride.

Highly Stereoselective Synthesis of Trifluoromethylated Compounds via Ester-Enolate [2,3]-Wittig and [3,3]-Ireland-Claisen Rearrangements.

gamma-Trifluoromethylated propargylic alcohols have been obtained in optically pure forms via effective enzymatic kinetic resolution and then converted into (E)- or (Z)-allylic alcohols. [2,3]-Wittig rearrangement of the corresponding [[gamma-(trifluoromethyl)allyl]oxy]acetic acid methyl esters afforded alpha-hydroxy-beta-(trifluoromethyl)-gamma,delta-unsaturated carboxylic acid methyl esters in good yields. The rearrangement of (Z)-substrates proceeded in a highly stereoselective manner to give anti-isomers with E configuration at a newly created olefinic bond via complete chirality transfer.