Reactions of ω-diphenylphosphinofunctionalized alkyl phenyl sulfides Ph2P(CH2)nSPh (n = 1, 1a; 2, 2a; 3, 3a), sulfoxides Ph2P(CH2)nS(O)Ph (n = 1, 1b; 2, 2b; 3, 3b) and sulfones Ph2P(CH2)nS(O)2Ph (n = 1, 1c; 2, 2c; 3, 3c) with dinuclear chlorido bridged rhodium(I) complexes [(RhL2)2(μ-Cl)2] (L2...

Fast and chemoselective desilylation of silyl-protected alcohols was achieved using a catalytic amount of 1-chloroethyl chloroformate in methanol. With a minimal amount of 1-chloroethyl chloroformate as the source for anhydrous HCl, extremely efficient cleavage of silyl ethers of primary and sec...

An efficient and convenient procedure for direct esterification of alkyl and aryl silyl ethers with Ac2O and a catalyst system of perchloric acid immobilized on a silica gel (HClO4–SiO2) has been developed. The silyl protecting groups are directly replaced by acetyls and the protecting groups t...

The reactivity of 2-aryl-5-trimethylsilyl-1,3,4-oxadiazoles toward different types of electrophiles was investigated. These silanes readily react with chlorine, bromine, aliphatic acyl chlorides, 2-nitrobenzenesulfenyl chloride, and some reactive isocyanates affording the corresponding substitut...

TFDA is readily prepared from the reaction of fluorosulfonyldifluoroacetic acid with trimethylsilyl chloride, and it is a very effective and efficient source of difluorocarbene for use in addition reactions to alkenes of a broad scope of reactivities. Acid-sensitive substrates may require an add...

A series of ortho and para-nitrobenzyl esters of short chain fatty acids (C2 to C5) and of the lipophilic aminoacid, l-valine, and some other o-nitrobenzylated products were prepared. Bioreductive or hydrolytic cleavages of these compounds could release both differentiation promoting agents such...

The synthesis of four diaza-18-crown-6 ethers with C2-symmetry derived from trans-(R,R)-1,2-diaminocyclohexane bearing methyl, phenyl and phenoxymethyl moeities attached to a stereogenic centre on the crown ring were achieved. Enantiomeric discrimination of these macrocycles against amino acid m...

A mixture of d-alloisoleucine and l-isoleucine derivatives are selectively hydrolysed by enzymatic catalysis (alcalase) allowing the recovery of the d-allo stereoisomer in excellent d.e. and yields. Thus, N-formyl-d-allo-isoleucine benzylester is obtained after enzymatic hydrolysis of the diaste...

Four new series of diastereomeric β,γ-di- and β,γ-tetrapeptides derived from conveniently protected (1R,2S)- and (1S,2S)-2-aminocyclobutane-1-carboxylic acid and cis- and trans-γ-amino-l-proline joined in alternation have been synthesized. High resolution NMR experiments show that peptides ...

l-Proline is a bifunctional versatile organocatalyst that could promote a variety of useful transformations. Some passive and dynamic interactions between this simple amino acid and different substrates, which are necessary to enzymatic reactions, have given it “the simplest enzyme” title. Her...

BackgroundWhile producing good-quality analgesia, µ-opioid (MOP) receptor activation produces a number of side-effects including tolerance. Simultaneous blockade of δ-opioid (DOP) receptors has been shown to reduce tolerance to morphine. Here, we characterize a prototype bifunctional opioid H-...

A method for the quantitation of α-fluoro-β-alanine (AFBA), the main metabolite of capecitabine (Cape) and 5-fluoruracil (5-FU), is described. Among antineoplastic drugs (ADs), 5-FU and Cape (the new oral prodrug) are the most commonly applied drugs in cancer therapy.The main objective of this...

The infra-red gaseous, liquid, solution and solid spectra of N-methylimidazole (MI), N-methyl-d3 imidazole (MDI) and N-methylimidazole-d3 (MID) have been studied in the 4000-200 cm−1 range. The Raman spectra of these compounds in liquid state have been investigated in the same spectral region. A...

A Gas Chromatography (GC) method has been developed for the separation and characterization of the different fatty acids in anhydrous milk fat (AMF) by means of an ionic liquid stationary phase, characterized by a monocationic imidazolium salt derived from l-phenylalanine. The inner surface of a...

A family of aromatic acids containing different binding sites, including 5-chloro-2-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, salicylic acid, 3-nitrophthalic acid, 4,5-dichlorophthalic acid, 6-hydroxy-2-naphthoic acid and tetrafluorophthalic acid, were allowed to react with 2,3-dimethylpyr...

Methoxydefluorination of 5,7-, 6,7-, 6,8-, and 5,8-difluoroquinoline (1–4) by the action of sodium methoxide has been studied in liquid ammonia and Me2SO. The regioselectivity of methoxydefluorination of 1 and 2 in the temperature interval 218–240 K in liquid ammonia and 1 and 4 in the interva...

Ductile composite scaffolds can avoid being crushed during filling processes in clinical applications. Thus, this study aimed to modify brittle porous ceramic scaffolds into ductile scaffolds through hydrogel capping. The surfaces of calcium phosphate (CaP) ceramic scaffolds were effectively cap...

Cardiovascular diseases (CVDs) are the main cause of deaths worldwide. Up-to-date, hypertension is the most significant contributing factor to CVDs. Recent clinical studies recommend calcium channel blockers (CCBs) as effective treatment alone or in combination with other medications. Being the ...

N-Alquil nitrones 1c and 3–6 were prepared from aromatic aldehydes and N-tert-butylhydroxylamine or N-methylhydroxylamine in good yields and soft conditions. Their protective effect against microvascular damages caused by ischemia/reperfusion in ‘hamster cheek pouch’ assay was investigated an...

Treatment of a range of O-protected glycolate derivatives of the chiral auxiliary N-1-(1′-naphthyl)ethyl-O-tert-butylhydroxylamine with KHMDS in the presence of 18-crown-6 followed by addition of an alkyl halide generates α-substituted derivatives with very high levels of diastereoselectivity....