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The mechanism of enamine-mediated organocatalytic [3 + 2] cycloaddition (32CA) reaction of Hagemann's ester to p-toluenesulfonyl azide in the present L-proline as a catalyst has been investigated using M06-2X functional with the 6-31+G(d) basis set. The effects of the different solvents were studied with a 6-311+G(d,p) basis set. In addition, the effects of the keto ester substitutions: one model system M1 (R1 = CH3 and R2 = H) and two real systems R2 (R1 = R2 = Me) and R3 (R1 = Et and R2 = Me) also studied in this work. DFT results indicated that the different solvents show the same effect, which leads to a decrease in the ΔG298 along the reaction pathway compared to the gas phase. Moreover, the model system M1 has a lower activation free energy (17.5 kcal/mol) than real systems R2 and R3 by about 3.8 and 3.2 kcal/mol in the solution phase (DMSO), respectively. Analysis of the global and local reactivity indices of the reactants was performed in the gas and solution phases. [ABSTRACT FROM AUTHOR]

An efficient one-pot sequential annulation of 1,n-enynes with tosyl azide is reported, providing a series of novel N -alkyl 1,2,3-triazole-fused polycyclic scaffolds in moderate to excellent yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

The present work describes the catalytic activity of nitrogen-doped TiO2 nanotubes (NTNTs) for solvent-free domino synthesis of a series of α-ketotriazoles from methyl ketones, N,N-dimethylformamide dimethyl acetal (DMF-DMA) and tosyl azide. The reaction proceeds through the in situ enaminone formation from methyl ketones and DMF-DMA followed by reaction with tosyl azide via a 1,3-dipolar cycloaddition. To our delight, NTNTs exhibited high catalytic activity towards the solvent-free synthesis of α-ketotriazoles from methyl ketones, DMF-DMA and tosyl azide as compared to both commercially available TiO2 and TNTs. The present domino strategy has several advantages which include its large substrate scope, low NTNT-2 loading, shorter reaction times and high yields. Further, the obtained α-ketotriazoles does not require column purification and NTNT-2 is used again for 7 cycles without significant loss of activity.

Diazo-transfer reaction of tosyl azide and alkyl 2-cyanoacetates in the presence of pyridine at 0 °C gives the corresponding alkyl 2-cyano-2-diazoacetates. This material readily undergoes nucleophilic attack by pyridinium 1-cyano-2-alkoxy-2-oxoethan-1-ide to form dialkyl (Z)-3-amino-2-cyano-4-diazopent-2-enedioates. The X-ray structure of a typical product is reported, as well as DFT computational studies that illuminate the structural features of these stable diazo compounds. [ABSTRACT FROM AUTHOR]

The annulation reactions between gem‐diamino enaminones (ketene aminals) and tosyl azide providing N‐heterocycle fused and 5‐amino side chain functionalized 1,2,3‐triazoles have been developed. The synthesis of these N‐side chain functionalized 1,2,3‐triazoles has been executed with high efficiency and broad synthetic scope under transition metal‐free conditions with the assistance of NaHCO3 only. [ABSTRACT FROM AUTHOR]

(5-Methyl-1,3-thiazolidin-2-ylidene) ketones, depending on the substituent in the ylidene part of the molecule, interact with tosyl azide to form (5,6-dihydro[1,3]thiazolo[3,2-c][1,2,3]triazol-3-yl) ketones and N-[(5,6-dihydro[1,3]thiazolo[3,2-c][1,2,3]triazol-3-yl)alkylidene]-tosylamides. [ABSTRACT FROM AUTHOR]

The synthesis of a novel class of N-(1H-benzo[d]imidazol-2-yl)-2-alkyl-N′-sulfonylacetamidines via a copper-catalyzed, three-component coupling reaction of 1H-benzo[d]imidazol-2-amine, sulfonyl azides, and terminal alkynes is described. [ABSTRACT FROM PUBLISHER]

It is demonstrated that phosphorotropic migration occurs in the C³NC5 triad of 1,4-benzodiazepines, which is accompanied by the isomerization of Ph2POC³ to Ph2P(O)C5. [ABSTRACT FROM AUTHOR]

Ketenimine intermediates generated by the addition of copper acetylides to sulfonyl azides are trapped by KSCN to afford N-sulfonylalkanimidoyl thiocyanates in moderate-to-good yields. [ABSTRACT FROM AUTHOR]

Ketenimine intermediates generated by the addition of copper acetylides to sulfonyl azides are trapped by ( p-toluenesulfonyl)methyl isocyanide (TsCH2NC), in the presence of Et3N, to afford functionalized pyrroles in moderate-to-good yields. [ABSTRACT FROM AUTHOR]

Ketenimine intermediates, generated by the addition of copper acetylides to tosyl azides, are trapped by alkyl isocyanides to yield N -alkyl-2-(sulfonylimino)alkanamides in moderate to good yields. [ABSTRACT FROM AUTHOR]

Abstract: Ketenimine intermediates generated by the addition of copper acetylides to sulfonyl azides are trapped by nitrile imines (generated from hydrazonoyl chlorides and triethylamine) to afford tetrasubstituted pyrazoles in moderate to good yields. [Copyright &y& Elsevier]