Computer-assisted mechanistic evaluation of organic reactions: Radical ion chemistry and photochemical reactions

CAMEO (Computer-Assisted Mechanistic Evaluation of Organic reactions) is an interactive computer program designed to predict the products of organic reactions given starting materials and reaction conditions. It arrives at its conclusions by using mechanistic reasoning and fundamental concepts concerning structures and reactivity. The program is under continuous development.;The chemistry of the free radical module has been expanded to include ;The program has also been enhanced to include free radical aromatic substitution reactions. This has required analysis of the key features governing reactivity and selectivity for this class of processes. For intermolecular free radical aromatic substitutions, attention has been focused on perception and classification of aromatic compounds and identification of the most reactive sites. For intramolecular free radical aromatic substitutions, reactivity and selectivity are governed by structural, substituent, steric, and electronic effects. Algorithms governing the chemo-, regio-, and stereoselectivities of these reactions derived from literature precedent have been implemented in the program.;The introduction of photochemistry has necessitated the addition of a photolytic module in CAMEO. Incorporation of photochemical reactions has included the implementation of electrocytic and (2+2) cycloaddition reactions. Concerted and biradical mechanisms are possible depending on the type of reacting compound, the excited state responsible for the reaction and the electronic nature of the olefins. Application of an FMO (Frontier Molecular Orbital) approach is the major tool for the implementation of these reactions. Both regioselectivity and stereospecificity are predicted.