Jean-Paul Pradère

Enchainements heteroatomiques et leurs produits de cyclisation—III : Réactions de Diels-Alder entre vinylogues de thioamides et diénophiles acryliques fonctionnels linéaires et cycliques. Propriétés chimiques des 2H-thiopyrannes liées aux substituants en position 2 et 3

Abstract The thioamide vinylogues (2-aminovinyl thioketones) react as heterodienes with open-chain and cyclic dienophiles to give substituted 4-amino-3,4-dihydro-2H-thiopyrans, or substituted 2H-thiopyrans and substituted 7 - methyl - 7,7a - dihydro - 5H - thiopyranno[2,3 - c] - 5 - furanones respectively, in good agreement with calculated perturbation energy of second order.

Synthesis of (+,−) 3,4-disubstituted 3,4-dihydro-2H-thiopyrans via a diastereoselective hetero Diels-Alder reaction

Abstract The behaviour of endo selective diene 4 in kinetically controlled hetero Diels-Alder cycloadditions is in marked contrast with that of its exo selective aza analogue 1 .

Lactamisation par le bop : acethyl-3 methyl-7 phtalimido-7 cepheme

Resume A 1,3-thiazine with a prelactamic chain is obtained via a (4+2) cycloaddition reaction. The regioselective hydrogenation at 2,3 and subsequent lactamisation using BOP is described.

Réductions électrochimiques et chimiques de phenyl-2 6H-thiazines-1,3

Abstract Electrochemical and chemical reductions of 2-phenyl 6H-1,3-thiazines are complementary methods for the regioselective hydrogenation of the heterocyclic structure.

1H NMR evaluation of the enantiomeric purity of a series of heterocyclic β-dimethylamino esters and amides by using (S)-mandelic acid derivatives as chiral solvating agents

Abstract ( S )-OR-Mandelic acid derivatives have been used as chiral solvating agents to induce significant non-equivalences in the 1 H NMR spectra of several heterocyclic structures bearing a β-dimethylamino ester or amide pattern.

The preparation and rearrangements of 5-acyl-2-phenyl-4-substituted 6H-1,3-thiazines. X-Ray molecular structure of 3-acetyl-2-ethoxycarbonyl-4-(3-oxobutylthio)-5-phenylpyrrole

5-Acyl-2-phenyl-4-substituted 6H-1,3-thiazines are prepared by the reaction of N′,N′-substituted N2-thiobenzoylformamidines with methyl vinyl ketone or acrylaldehyde. Rearrangement catalysed by base and subsequent condensation with the acrylic reagent gives substituted pyrrolyl sulphides or substituted 2,6-dihydrothiopyrano[2,3-c]pyrrole.

A selective electrochemical way to functionalized 6H-1,3-thiazines and /or pyrroles.

Abstract Controlled Potential Electroreduction (C.P.E) of functionalized 4H-1,3-thiazines, easily prepared from 1-thia-3-azabutadienes leads to substituted 6H-1,3-thiazines or pyrroles in protic medium.

The hetero Diels–Alder reaction featuring 2-phenyl-4-dimethylamino-1-thia-3-azabuta-1,3-diene as diene component: a clear example of a thermodynamically-controlled process

Abstract Cycloaddition reactions of diene 1a with various dienophiles lead to trans 4,5-disubstituted dihydro-1,3-thiazine adducts. We demonstrate that a thermodynamically-controlled process, in which the adduct N-3 nitrogen plays a prominent role, accounts for the observed trans relative configuration.

Selective reduction of 4h-1,3-thiazine-4-ones : Easy access to substituted 6h-1,3-thiazines

Abstract Selective reduction of 4H-1,3-thiazine-4-ones leads to new substituted 6H-1,3-thiazines. The isomerisation from 6-to 5-methoxycarbonyl-6H-1,3-thiazines via substituted 4-acetoxy-1-thia-3-aza-butadienes by a cycloreversion-cycloaddition process can be performed in one step.

Oxidative ring opening of 2-pyrazolines. Application to lactamisation and formylation of 1,3-6h-thiazines.

Abstract Benzeneseleninic anhydride allows oxidative ring opening of 2-pyrazolines to α,β-unsaturated carbonyl compounds. Thus, a pyrazoline ring may be used as a masking, a stereodirecting and a latent formyl group in the synthesis of 7-amino 4-formyl cephem from 1,3-6H-thiazine.