Dimerization of Functionalized Isoindenones
Pericyclic reactions are ubiquitous in organic synthesis and represent a major strategy for synthesizing polycyclic organic compounds. The concept of secondary orbital interactions (SOI) was first introduced by Woodward and Hoffmann and has been used to understand the regioselectivity of pericyclic reactions. Furthermore, understanding SOIs has given chemists the capability to explain the prevalence of endo over exo products in cycloadditions. Isoindenone and its derivatives exhibit unique reactivity due to the presence of an additional aromatic ring in the monomer compared to the analogous dimerization of cyclopentadienone. The dimerization of cyclopentadienone has been shown by theory and experiment to yield the endo adduct, while work by Etzkorn et al. has shown that the unsubstituted isoindenone can dimerize to form a [4+4] dimer. Subsequently, this isoindenone dimer has been synthesized following a new synthetic approach and using a variety of functionalized monomers, some leading successfully to dimerization while others do not. Here we propose the study of the isoindenone dimerization, and the effect of substituents on this reaction using a combination of density functional theory and complete active space calculations.  P. Quadrelli, S. Romano, L. Toma, and P. Caramella. J. Org. Chem. 2003, 68, 6035-6038.  M. Etzkorn, S. D. Smeltz-Zapata, T. B. Meyers, X. Yu, and M. Gerken. Tetrahedron Letters, 2010, 51, 6075-6077.
Bernard Osemwenkhae, Osamakon, "Dimerization of Functionalized Isoindenones" (2020). IdeaFest. 53.