4 research outputs found
A Facile Regioselective Synthesis of Novel Spiroacenaphthene Pyrroloisoquinolines Through 1,3-Dipolar Cycloaddition Reactions
No full textAn 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
A theoretical investigation on the regioselectivity of the intramolecular hetero Diels-Alder and 1,3-dipolar cycloaddition of 2-vinyloxybenzaldehyde derivatives
No full textThe 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
