We report the direct observation of a bent geometry for a nonstabilized nitrile imine in a metal-coordination crystal. The photoinduced tetrazole ring rupture to release N(2) appears to depend on the size of voids around the N(3)-N(4) bond in the crystal lattice. We further observed the selective formation of the 1,3-addition product when a reactive nitrile imine was photogenerated in water. Ov...

In the presence of 1 mol% of a copper(II) catalyst and air, a readily available N-acetyl-N-thioacylguanidine undergoes a one-pot benzylic oxidation–oxidative heterocyclization sequence to give the 3-amino5-acyl-1,2,4-thiadiazole core of polycarpathiamines A (2) and B (3) and thus facilitating the first synthesis of both natural products. This methodology offers a straightforward alternative to ...

The reactivity of 2-oxindoles bearing a C=X double bond (X=C<, N?, O) in the 3-position towards variety 1,3-dipolar species has been reviewed systematic way according to type 1,3-dipole, 2-oxindole dipolarophile, and racemic or asymmetric nature cycloaddition. Because great resulting spiro-2-oxindole skeletons, developments occurred 2010–2020 decade were taken into account.

An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-halo-1H-pyrazoles are found to be important intermediates that can easily be converted into 1,2,5-triaryl-substituted pyrazoles via Pd-catalyz...

Cycloaddition reactions represent one of the most powerful processes in organic chemistry. The most common types of cycloaddition reactions are the Diels-Alder (DA) and the 1,3-dipolar cycloaddition reactions (1,3-DCs) which lead to five and six membered rings, respectively. In our ongoing efforts to contribute to the understanding of DA and 1,3-DCs; we studied the following using the B3LYP/6-3...

A unified biomimetic approach to the aglain-forbaglin-rocaglamide classes of natural products is reported. The approach involves photogeneration of oxidopyryliums via excited-state intramolecular proton transfer (ESIPT) of 3-hydroxyflavones followed by [3+2] dipolar cycloaddition to the aglain core. An alpha-ketol (acyloin) rearrangement was employed to transform the aglain core to the rocaglam...

Phosphonated isoxazolinyl nucleosides have been prepared via 1,3-dipolar cycloaddition reaction of nitrile oxides with corresponding vinyl or allyl nucleobases for antiviral studies. The cytotoxicity, the anti-HSV activity and the RT-inhibitory activity of the obtained compounds were evaluated and compared with those of AZT and diethyl{(1'SR,4'RS)-1'-[[(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1...

A series of spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9-22 μM. Biological tests suggest that the...