2′-Methyl-2′-nitro-1′-phenyl-2′,3′,5′,6′,7′,7a’-hexa­hydro­spiro­[indoline-3,3′-1′H-pyrrolizin]-2-one

The title compound, C21H21N3O3, was synthesized by a multi-component 1,3-dipolar cyclo­addition of azomethine ylide, derived from isatin and proline by a deca­rboxylative route, and (E)-1-phenyl-2-nitro­propene. In the mol­ecule, the spiro junction links a planar oxindole ring and a pyrrolidine ring in an envelope conformation. The mol­ecular packing is stabilized by an inter­molecular N—H⋯N inter­action of the oxindole and pyrrolizidine rings

A theoretical investigation on the regioselectivity of the intramolecular hetero Diels-Alder and 1,3-dipolar cycloaddition of 2-vinyloxybenzaldehyde derivatives

The present study reports a systematic computational analysis of the two possible pathways, fused and bridged, for an intramolecular hetero Diels-Alder (IMHDA) and an intramolecular 1,3-dipolar cycloaddition (IMDCA) of 2-vinyloxybenzaldehyde derivatives. The potential energy surface analysis for both reactions is in agreement with experimental observations. The activation energies associated with the two regioisomeric channels in IMHDA reaction show that the bridged product is favored, although in IMDCA, the most stable TS results the fused product. The global electronic properties of fragments within each molecule were studied to discuss the reactivity patterns and charge transfer direction in the intramolecular processes. The asynchronicity of the bond formation and aromaticity of the optimized TSs in the Diels-Alder reaction as well as cycloaddition reaction were evaluated. Finally, 1H NMR chemical shifts of the possible regioisomers have been calculated using the GIAO method which of the most stable products are in agreement with the experimental data in the both reaction

A Facile Regioselective Synthesis of Novel Spiroacenaphthene Pyrroloisoquinolines Through 1,3-Dipolar Cycloaddition Reactions

An efficient one-pot three-component procedure for the synthesis of novel spiroacenaphthene pyrroloisoquinolines with high regioselectivity is described. These compounds were prepared from 1,3-dipolar cycloaddition of an azomethine ylide generated from acenaphthenequinone and 1,2,3,4-tetrahydroisoquinoline via [1,5]-H shift, with chalcone and nitrostyrene derivatives as dipolarophiles. The structure and stereochemistry of the cycloadducts have been established by single crystal X-ray structure and spectroscopic techniques