Abdesselam Baouid

Synthesis of New Tri- and Tetraheterocyclic Systems: 1,3-Dipolar Cycloaddition of Nitrilimines on 2,7-Dimethyl-4-Phenyl-3H-1,5-Benzodiazepine

Abstract We report here a one-step synthesis of a new series of tri and tetraheterocyclic systems by the mixed condensation reactions of N-aryl-C-ethoxycarbonylnitrilimines and diarylnitrilimines with 2,7-dimethyl-4-phenyl-3H-1,5-benzodiazepine This 1,3-dipolar cycloaddition is completely peri and regioselective The structure of these products has been confirmed by 1H, 13C NMR, mass spectroscopic and X-ray crystallographic analysis.

Highly regio- and diastereoselective 1,3-dipolar cycloaddition of nitrile oxides to 2,4-dimethyl-3h-1,5-benzodiazepines: Synthesis of bis[1,2,4-oxadiazolo][1,5] benzodiazepine derivatives

Abstract The 1,3‐dipolar cycloaddition reaction of nitrile oxides to 2,4‐dimethyl‐3H‐1,5‐benzodiazepines 1a–1c led, with completely regio‐ and diastereoselectivity, to new 3a,4a,8,13‐tetrahydro‐4H‐bis[1,2,4‐oxadiazolo][4,5‐a:5′,4′‐d][1,5]benzodiazepines 3a–3g. The structures of the synthesized bis‐adducts 3a–3g were elucidated by spectral methods and X‐ray crystallographic analysis.

Highly peri-, regio- and diastereoselective 1,3-dipolar cycloaddition of mesitonitrile oxide to 1,7-dimethyl-2,3-dihydro-1H-1,4-diazepines: unexpected one-step formation of a new triheterocyclic framework

We report here an efficient one-step synthesis of new [1,2,4]oxadiazolo[4,5-d][1,4]diazepines and [1,2,4]oxadiazolo[4,5-d][1,4]-diazepine-8-spiro-5′-isoxazolines by way of highly peri-, regio- and diastereoselective 1,3-dipolar cycloadditions of mesitonitrile oxide to 1,7-dimethyl-2,3-dihydro-1H-1,4-diazepines. The structures were elucidated by spectral methods and X-ray crystallographic analysis. The regiochemistry of the cycloaddition is dictated by frontier orbital interactions.

Synthesis of Novel [1,2,4]Triazolo[3,4-d][1,5] Benzodiazepinones Derivatives by 1,3-Dipolar Cycloaddition

Abstract Cycloaddition of N-aryl-C-ethoxycarbonylnitrilimines and diarylnitrilimines on 1,5-benzodiazepinones was achieved in a one-pot procedure, to give a variety of compounds possessing an additional heterocyclic ring fused to the heterocyclic nucleus. This reaction was revealed to be completely peri and regioselective. The structures were elucidated by spectral methods and X-ray crystallographic analysis.

1,3-Dipolar cycloaddition of nitrilimines to 2,4-disubstituted-3H-1,5-benzodiazepines: remarkable effect of C4-substituent on diastereoselectivity

The one-step synthesis of new bis[1,2,4-triazolo][4,3-a:3′,4′-d][1,5] benzodiazepines by way of completely regio- and diastereoselective 1,3-dipolar cycloaddition of nitrilimines to 2,4-dimethyl-3H-1,5-benzodiazepines is reported and a tentative rationalization for the observed diastereoselectivity, which underline the key effect of the C4-dipolarophile substituent, is proposed.

Peri and Regioselective Synthesis of New Heterocyclic Compounds from 1,5-Benzodiazepines

Abstract Condensation of nitrilimines with 1,5-benzodiazepines was achieved in a one-pot procedure, to give a variety of new heterocyclic compounds. This reaction was found to be completely peri and regioselective. The new structures were elucidated by spectral methods and confirmed by X-ray crystallographic analysis.

Synthesis of New Tetraheterocyclic Systems by the Mixed Condensation Reactions on [1,2,4]Triazolo[4,3‐a][1,5]benzodiazepines

Abstract We report here a one step synthesis of a new series of bis‐[1,2,4‐triazolo][4,3‐a:3′,4′‐d][1,5]benzodiazepines 3a–e and [1,2,4]oxadiazolo[5,4‐d][1,2,4]triazolo[4,3‐a][1,5]benzodiazepines 5a–c by the condensation reactions of diarylnitrilimines and arylonitrile oxides. This 1,3‐dipolar cycloaddition is completely regioselective. The structure of these products has been confirmed by 1H, 13C NMR and mass spectroscopic.

2α,3α:6α,7α-Diépoxyhimachalane

The stereochemistry of the minor isomer, 3,4: 9,9a-diepoxy-3,5,5,9-tetramethyldecahydro- 1H-benzocyclo-heptene, C15H2402, resulting from the epoxidation of β-himachalene has been established. The atoms C10 and the gem-dimethyl groups C14 and C15 adopt two positions leading to two conformations for the seven-membered ring, boat-shaped (occupation factor 70%) and chair-shaped (30%). Modelling of these conformations agrees with the statistical distribution in the crystal.

Some 1,3-Dipolar Adducts from Benzodiazepine. I. Condensation of Nitrilimines with 2-Methyl-4-phenyl-1,5-benzodiazepines

The condensation reaction of N-p-nitrophenyl-C-ethoxycarbonyl nitrilimine or N-p-chlorophenyl-C-ethoxycarbonyl nitrilimine with 7-X-2-methyl-4-phenyl-1,5-benzodiazepine (X = H or CH 3 ) is regio- and periselective. The 1,3-dipolar cycloaddition occurs in a unique way on the N1≡C2 double bond of the 1,5-benzodiazepine and leads to ethyl 3a-methyl-3-(4-nitro-phenyl)-5-phenyl-3a,4-dihydro-3H-[1,2,4]triazolo [4,3-a][l,5]benzodiazepine-1-carboxylate, C 26 H 23 N 5 O 4 , (3a), or ethyl 3-(4-chlorophenyl)-3a,8-dimethyl-5-phenyl-3a,4-dihydro-3H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepine-1-carboxylate, C 27 H 25 ClN 4 O 2 , (3b).

1-(4-Chlorophenyl)-3a-methyl-5-phenyl-3a,4-dihydro-1,2,4-oxadiazolo[4,5-a][1,5]benzodiazepine

We report here the peri- and regioselectivity experienced in the 1,3-dipolar cycloaddition of 1,5-benzodiazepine to a nitrile oxide. The crystal structure of the title cycloadduct, C 23 H 18 ClN 3 O, shows that the condensation occurs at the N=C double bond at the 1 and 2 positions of the benzodiazepine.