Vincenzo Bertini

1,3-Dithiane polymers for the supported synthesis of ketones

Abstract The synthesis of polymeric reagents containing an odourless propane-1,3-dithiol functionality is reported. Their usefulness for the solid phase synthesis of ketones via the umpoled alkylation of 1,3-dithianes is demonstrated.

Unexpected behavior of the methoxymethoxy group in the metalation/formylation reactions of 3-methoxymethoxyanisole

The formation of tetrasubstituted benzenes and doubly lithiated intermediates in metalation/formylation reactions of 3-methoxymethoxyanisole has been observed with the methoxymethoxy group acting as a leaving group in some cases.

Vinyl monomers containing 1,2-thia-, selena- and tellurazole systems, their polymers and copolymers

Synthese de ces monomeres, homopolymerisation radicalaire et copolymerisation avec le styrene

Vibrational spectra and normal mode calculations of 1,2,5-telluradiazole

Abstract the vibrational spectrum of 1,2,5-telluradiazole is investigated in the 4000-50 cm −1 region by i.r. and Raman spectroscopy. Infrared spectra of solid samples are also measured at 10 k. A satisfactory assignment of all the fundamentals is obtained by employing a valence force field which provided a complete set of normal coordinates suitable to describe the vibrational spectra of selenophene, tellurophene and 1,2,5-selenadiazole. Relations between the vibrational spectrum and the pseudopolymeric crystal structure of 1,2,5-telluradiazole are discussed.

On the base catalysed ring opening of 3-unsubstituted isoxazoles. Derivatives of 4- and 5-phenylisoxazole

The kinetics of the base-induced decomposition of 4- and 5-phenylisoxazole and their p-bromo- and p-nitrophenyl derivatives, and 3-deuterio-5-phenylisoxazole, to the corresponding cyanoenolate anions have been studied. The mechanism of reaction has been established as a one-stage concerted abstraction of the proton in position 3 and scission of the N–O bond. 4-Phenylisoxazole, previously synthesized by laborious methods, has been prepared by a simpler procedure.

Vinyl derivatives of heterocyclic systems and their polymers: 3-vinyl-1,2,5-thiadiazole

Abstract 3-Vinyl-1,2,5-thiadiazole is prepared by different methods: by one-pot reaction from 1,2,5-thiadiazole, by cyclization of 3,4-diamino-1-butene, and by the Wittig procedure either from 1,2,5-thiadiazolylimethylenetriphenyl-phosphorane or from 3-formyl-1,2,5-thiadiazole. Some physical and chemical properties are described.

3,4-(Methylenedioxy)benzyl acrylate/acrylic acid copolymers as selective pH-controlled flocculants for finely divided titanium minerals

Abstract Fully synthetic tailor-made radical copolymers of 3,4-(methylenedioxy)benzyl acrylate with acrylic acid afforded excellent pH-controlled selective flocculation of aqueous ultrafine dispersions of the titanium minerals rutile and ilmenite. Sedimentation experiments proved that the copolymers, characterized by osmotic molecular weights in the range of 35 000–476 000 Da, produced stable, well separable flocs with rutile or ilmenite at acidic pH while they did not flocculate gangue minerals such as quartz. They showed the distinctive, very useful property of reversibly changing their effect from flocculation to dispersion or neutral by changing the pH. The formation of flocs is interpreted on the basis of a preliminary gathering process of the particles determined by the pH-dependent alteration of the particle surface solvation carried out with the copolymer.

New synthesis of 1,2,5-selenadiazoles

Synthese par reaction de thiadiazole-1,2,5 ou de derives monosubstitues avec un reactif de Grignard puis le melange SeCl 4 /Se (correspondant a SeCl)

Synthesis of isoselenazole and its 3- and 5-substituted derivatives

Abstract A new method of synthesis for isoselenazole and its 3- and 5-substituted derivatives by one-pot procedure which uses α-acetylenic aldehydes or ketones besides hydroxylamine-O-sulphonic acid and potassium selenide in buffered aqueous solution, is described. When α-acetylenic aldehydes are used, selenobisalkenylnitriles are obtained as side products.

Synthesis of 2,6-disubstituted benzylamine derivatives as reversible selective inhibitors of copper amine oxidases

In order to obtain substrate-like inhibitors of copper amine oxidases (CAOs), a class of enzymes involved in important cellular processes as well as in crosslinking of elastin and collagen and removal of biogenic primary amines, we synthesized a set of benzylamine derivatives properly substituted at positions 2 and 6 and studied their biological activity towards some members of CAOs. With benzylamines 6, 7, 8 containing linear alkoxy groups we obtained reversible inhibitors of benzylamine oxidase (BAO), very active and selective toward diamine oxidase (DAO), lysyl oxidase (LO) and monoamine oxidase B (MAO B) characterized by a certain toxicity consequent to the crossing of the brain barrier. Poorly toxic, up to very active, reversible inhibitors of BAO, very selective toward DAO, LO and MAO B, were obtained with benzylamines 10, 11, 12 containing hydrophilic ω-hydroxyalkoxy groups. With benzylamines 13, 14, 15, containing linear alkyl groups endowed with steric, but not conjugative effects for the absence of properly positioned oxygen atoms, we synthesized moderately active inhibitors of BAO reversible and selective toward DAO, LO and MAO B. The cross examination of the entire biological data brought us to the conclusion that the bioactive synthesized compounds most likely exert their physiological role of reversible inhibitors in consequence of the formation of a plurality of hydrogen bonds or hydrophobic non-covalent interactions with proper sites in the protein. Accordingly, the reported inhibitors may be considered as a set of research tools for general biological studies and the formation of enzyme complexes useful for X-ray structure determinations aimed at the design of more sophisticated inhibitors to always better modulate the protein activity without important side effects.