Antonio Arques

Synthesis of the novel chiral 1,3-amino alcohol 8-N,N-bis(ferrocenylmethyl)amino-menthol and its use as catalyst in the enantioselective addition of diethylzinc to aldehydes

Abstract Optically active 8-N,N-bis(ferrocenylmethyl)aminomenthol 5, obtained by condensation of (−)-aminomenthol with ferrocenecarboxaldehyde followed by N-alkylation with (ferrocenylmethyl)trimethylammonium iodide and further reduction, was found to catalyze (5 mol%) the enantioselective ethylation of aromatic, aliphatic and organometallic aldehydes to secondary alcohols with high enantioselectivities (up to 95%) at room temperature.

Intramolecular trapping of a phosphazide by an imine: Formation of 2,3-diamino-2H-indazole derivatives from o-azidobenzaldimines and tertiary phosphines

Abstract Treatment of o-azidobenzaldimines with tertiary phosphines in dichloromethane at 0°C gave the corresponding 2,3-diamino-2H-indazole derivatives in good yields via the Staudinger reaction followed by cyclization of the intermediate phosphazide.

Synthesis and Structure of P,N-Heterodifunctional Ferrocene Ligands and their Transition Metal Complexes for Palladium-Catalyzed Aryl Amination Reaction

Abstract The Staudinger reaction of the β-ferrocenylvinylazide 1 with di- and triphosphines provided a new range of P,N-heterodifunctional ferrocene ligands bearing an iminophosphorane and at least a diphenylphosphino group; reactivity towards Pd (II) and the ability of the resulting complexes for palladium catalyzed aryl amination reaction is described.

Preparation and synthetic applications of iminophosphoranes derived from o-substituted arylazides: preparation of pyrazolo[1,2-b]indazole, 4H-3,1-benzoxazine and quinoline derivatives. Crystal structure of 2-[2-(4-methoxybenzoylamino)phenyl]-4-methylquinoline.

Abstract The Staudinger reaction of several ortho-substituted arylazides with triphenylphosphine has been studied. The reaction product is found to be strongly dependent on the nature of the ortho-substituent. The Aza Wittig-type reaction of iminophosphorane derived from the ortho-azido acetophenone with isocyanates and aroyl chlorides leads to the previously unreported 4-methylene-4H-3,1-benzoxazine ring. The crystal and molecular structure of 2-[2-(4-methoxybenzoylamino)phenyl]-4-methylquinoline has been established by X-Ray diffraction methods.

THE STAUDINGER REACTION OF O-AZIDOBENZALDEHYDE WITH TRIPHENYLPHOSPHINE REVISITED : INFLUENCE OF THE TEMPERATURE ON THE NATURE OF THE REACTION PRODUCTS

The reaction of o-azidobenzaldehyde 1 with TPP at 0°C leads to the expected iminophosphorane 2 and the indazole derivative 3 while at −20°C the phosphazide 4 was the only reaction product. The close related compounds 2 and 4 shows stricking differences in reactivity towards primary amines.

Synthesis and X-ray crystallographic study of 6,12-epiiminodibenzo[b,f][1,5]diazocines

Abstract Seven 6,12-epiiminodibenzo[b,f][1,5]diazocines 2 with different substituents at position 13 have been prepared from o-(triphenylphosphoranylideneamino)benzaldehyde 1 and the corresponding aliphatic and aromatic primary amines in yields ranging from 40 to 80%. The molecular and crystal structures of componds 2d (R = 4 H3C-C6H4) and 2e (R = 4 H3CO-C6H4) have been determined by X-Ray analysis. Compound 2d crystallizes as a racemate while compound 2e crystallizes as a unique enantiomer (absolute configuration R,R).

Iminophosphorane-mediated synthesis of functionalized indoles and 1,3-benzodiazepines

Abstract Aza Wittig-type reaction of bis(iminophosphorane) 2 with aromatic isocyanates leads to either indoles 5 or pyrimido[4,5-b]indoles 6 , whereas with aliphatic isocyanates and acyl chlorides afforded pyrrolo[2,3-b]indoles 7 and 1,3-benzodiazepines 10 respectively.

Heterocumulene-mediated annelation of a [1,3,4]thiadiazine or [1,3,4]oxadiazine ring into an imidazole ring: preparation and crystal structure of some derivatives of the unknown imidazo[1,5-d]-[1,3,4]thiadiazine and imidazo[1,5-d́][1,3,4]oxadiazine ring systems

Abstract The aza-Wittig reaction of iminophosphorane 2 derived from 1 -amino-3-phenyl-2-thioxo-4-imidazolidinone 1 with heterocumulenes leads to fused imidazoles. Iminophosphorane 2 reacts under mild conditions with isothiocyanates to form imidazo[1,5-d]-[1,3,4]thiadiazines 3 which undergo S-methylation to give imidazo[1,5-d][1,3,4]thiadiazinium salts 4. Iminophosphorane 2 also reacts with isocyanates under mild conditions to give imidazo[1,5-d][1,3,4]oxadiazines 5. The N-aminoheterocycle 1 by the action of diaryl carbodiimides undergoes ring-closure/ring-opening reaction to give the corresponding [1,2,4]triazoles 7, which by sequential treatment with trimethyloxonium tetrafluoroborate and triethylamine/methanol are converted into the oxygen analog 9. The crystal structure of the hydrated salt 4a has been solved by X-Ray diffraction methods. The two independent cations form dimers that pack in chains along the b axis through hydrogen interactions, in such away that all anions and solvent molecules (H2O and 2 HCCl3 in the asymmetric unit) are located in the unit cell into two channels which are described.

Tandem aza-wittig reaction/electrocyclic ring-closure a facile entry to the synthesis of fused pyrimidines: Preparation of pyrazolo[3,4-d] and 1,2,3-triazolo[4,5-d]pyrimidine derivatives.

Abstract The aza-Wittig reaction of iminophosphoranes derived from 5-azido-4-formyl azoles, with isocyanates or carbon disulfide, leads to functionalized fused pyrimidines.

One-pot synthesis of a new class of fused 2,4-diimino-1,3-diazetidines by an aza-Wittig/[2 + 2] cycloaddition of carbodiimides process

The new [5.7.4]tricyclic ring system 3 is synthesized in a one-pot reaction from bis(iminophosphorane)1 and two equivalents of aryl isocyanate; compound 1 also reacts with one equivalent of isocyanate to give the bicyclic [1,3]diazepine 6; the crystal structure of compounds 3 and 6 are determined.