1,3-dipolar addition of phenylazide to the carbon-carbon double bond: An ab initio study

With use of density functional methods and large basis sets, as implemented in the Jaguar v. 3.0 ab initio electronic structure package, we calculated the activation energy of the 1,3-dipolar addition of phenylazide to 19 dif ferent reactants containing a carbon-carbon double bond. The results provid e an excellent prediction of the relative reaction rates observed experimen tally as the substituents of the reactant are varied. Regioselectivity of t he products of the reaction also are predicted reliably by the calculations . The use of a large experimental data set and full representation of the r eactant species (as opposed to smaller model systems) provided a high degre e of confidence in the ability of the electronic structure methods to repro duce experimental data reliably. The effects of method of geometry optimiza tion and inclusion of solvation effects were investigated and found to be r elatively small.