55849-06-4Relevant academic research and scientific papers
Hydrogen Transfer Reactions, 20. - Competitive Pericyclic Reactions of Dihydro Arenes with Strained Cycloalkenes and Cycloalkynes
Gerres, Thomas,Heesing, Albert
, p. 1431 - 1438 (2007/10/02)
While several highly strained cycloalkenes and cycloalkynes react with dihydroarenes to give products of Diels-Alder or ene reactions only, 7 dehydrogenates two dihydroarenes as well.Semiempirical AM1 calculations on the transition structures for the cycloadditions and the hydrogen transfer reactions show the independence of their geometry from the starting compounds.The preference for dehydrogenations by 7 is caused by both steric and solvent effects. Key Words: Cycloadditions / Hydrogen transfer / Ring strain / Calculations, AM1 / Transition states
Hydrogen Transfer Reactions, 21. - On the Pericyclic Hydrogen Transfer from 1,2-Dihydroarenes to a Cycloheptyne
Gerres, Thomas,Heesing, Albert
, p. 1439 - 1448 (2007/10/02)
The aromatization of 1,2-dihydroarenes by thiacycloheptyne 1 takes place by a pericyclic process.This mechanism is supported by the dependence of the reactivity on the ? system, absence of both substituent and solvent effects, a strong negative entropy of activation, high stereoselectivity of hydrogen abstraction, as well as size and consistency of primary isotope effects and semiempirical calculations of the transition state.Key Words: Hydrogen transfer, pericyclic / Aromatization / Isotope effects / Ring strain
