Radical Stabilization Algorithm as a Predictive Tool for Novel and Reported Noncanonical Thiele’s Acid Analogues

Abstract

We recently showed that a simple radical-stabilization algorithm outperformed traditional frontier-molecular orbital methods for rationalizing the outcome of the venerable Thiele’s acid (or ester) Diels–Alder dimerization. In the present Communication, we describe a novel noncanonical Thiele-type dimerization of a cyclopentadiene phosphine oxide, and show that when steric factors are taken into account the ­radical-stabilization method once again correctly rationalizes the regio­chemical outcome for the reaction. We further show that the method appears to be general for all known Thiele- and half-Thiele dimerization events.

Production and Dynamic Mechanical Analysis of Macro-Scale Functionalized Polydicyclopentadiene Objects Facilitated by Rational Synthesis and Reaction Injection Molding

“…As shown in Figure (and presented in more detail in the Supporting Information), extensive spectroscopic analysis revealed the presence of the four species that had been described previously (heterodimers 4 and 9 , together with homodimers 11 and 12 ), along with one additional minor regioisomer ( 10 ) visible in the crude NMR spectrum. The connectivity of the newly identified regioisomerwhich is consistent with our earlier mechanistic predictions , (see Figure S2)establishes within the molecule a strained norbornyl CC double bond without any additional substituents. We were therefore concerned that 10 might participate in the polymerization reaction alongside 4 or, worse yet, react nonproductively with the ruthenium catalyst to shut down the reaction.…”

Click Chemistry with Cyclopentadiene

“…The origin of the product distribution has been of great interest to experimental and theoretical chemists. Explanations for the selectivity enlisting frontier molecular orbital theory, , bent bond theory, , and paralocalization energies have been put forth. Photochemical intramolecular [2 + 2] cycloaddition of Thiele’s ester and other endo -dicyclopentadienes allows access to functionalized 1,3-bishomocubane polycyclic cages. − …”