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Spirocyclization enhances the Diels-Alder reactivities of geminally substituted cyclopentadienes and 4H-pyrazoles.

ABSTRACT: The Diels-Alder reactivity of 5-membered dienes is tunable through spirocyclization at the saturated center. As the size of the spirocycle decreases, the Diels-Alder reactivity increases with the cyclobutane spirocycle, spiro[3.4]octa-5,7-diene, being the most reactive. Density functional theory calculations suggest that spiro[3.4]octa-5,7-diene dimerizes 220,000-fold faster than 5,5-dimethylcyclopentadiene and undergoes a Diels-Alder reaction with ethylene 1,200-fold faster than 5,5-dimethylcyclopentadiene. These findings show that spirocyclization is an effective way to enhance the Diels-Alder reactivity of geminally substituted 5-membered dienes.

SUBMITTER: Levandowski BJ

PROVIDER: S-EPMC10038129 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature

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Spirocyclization enhances the Diels-Alder reactivities of geminally substituted cyclopentadienes and 4H-pyrazoles.

Levandowski Brian J BJ Abularrage Nile S NS Raines Ronald T RT

Journal of physical organic chemistry 20221213 4

The Diels-Alder reactivity of 5-membered dienes is tunable through spirocyclization at the saturated center. As the size of the spirocycle decreases, the Diels-Alder reactivity increases with the cyclobutane spirocycle, spiro[3.4]octa-5,7-diene, being the most reactive. Density functional theory calculations suggest that spiro[3.4]octa-5,7-diene dimerizes 220,000-fold faster than 5,5-dimethylcyclopentadiene and undergoes a Diels-Alder reaction with ethylene 1,200-fold faster than 5,5-dimethylcyc ...[more]

PMID: 36968255

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