Accessing the Cloke-Wilson Rearrangement via Conjugate Addition of Phosphoranes to Michael Acceptors: A Route to Cyclopropanes and 5-Membered Ring Heterocycles Investigated by Density Functional and Ab Initio Theory
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Conjugate addition of unstabilized Wittig-type phosphonium ylides to 1,1-diacceptor- and 1-acceptor-substituted alkenes is investigated by density functional theory and high-level ab initio (DLPNO–CCSD(T)) calculations. The results indicate that the initial conjugate addition step should be facile with barriers predicted to be between 0 and 21 kcal mol –1 . Potential intramolecular follow-up reactions include the formation of acceptor-substituted cyclopropanes as well as the formation of dihydrofuran derivatives via intramolecular S N 2-type transition state structures. The barriers calculated for these potentially valuable cyclization reactions are substantial with Gibbs free energies of activation between 19 and 40 kcal mol –1 . Competing reaction channels include Wittig olefination (for ketones and aldehydes), as well as Claisen condensation reactions. The reaction offers an alternative entry point to the nucleophile-catalyzed Cloke-Wilson rearrangement.
Source: The Journal of Organic Chemistry
Author: Götz Bucher
Institution: University of Glasgow
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4401541572