title: Mechanistic aspects of superacid mediated condensation of polyphenols with ketones. Implications for polymer synthesis.
abstract: A detailed computational study of possible reaction paths for methanesulfonic and triflic acid mediated polyhydroxyalkylation reaction between resorcinol and trifluoracetone accompanied by cyclodehydration to give 9H-xanthene containing polymers has been carried out at M06-2X/6-311+G level of theory. A cluster solvation model was used for the calculations. The calculations revealed that the most kinetically favorable reaction path involves the cyclodehydration occurring during the polymer forming step. In this case 9H-xanthene formation is promoted by the activated phenyl ring in Wheland intermediate assisting the aromatic nucleophilic substitution of OH group which leads to the cyclization. It has been demonstrated that the inability of methanesulfonic acid to catalyze the formation of 9H-xanthene containing polymers is due to the very high barrier of the rate limiting step of the polymer forming reaction and not the cyclodehydration process.
authors.affiliation: Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, CU, Coyoacán, Mexico, DF, 04510, Mexico.
authors.forename: Gustavo
authors.initials: G
authors.lastname: López
authors.forename: Olivia H
authors.initials: OH
authors.lastname: Cruz
authors.forename: Lilian I Olvera
authors.initials: LI
authors.lastname: Garza
authors.forename: Mikhail G
authors.initials: MG
authors.lastname: Zolotukhin
authors.forename: Serguei
authors.initials: S
authors.lastname: Fomine
mesh_terms: D002384:Catalysis; D003198:Computer Simulation; D004735:Energy Transfer; D007700:Kinetics; D008698:Mesylates / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis*; D012118:Resorcinols / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013696:Temperature; D014269:Trifluoroacetic Acid / Q000737:chemistry*; D014966:Xanthenes / Q000138:chemical synthesis*
chemical_list: D008698:Mesylates; D011108:Polymers; D012118:Resorcinols; D014966:Xanthenes; C045880:methanesulfonic acid; D014269:Trifluoroacetic Acid; C012077:trifluoromethanesulfonic acid; C031389:resorcinol