6533b861fe1ef96bd12c55c0

RESEARCH PRODUCT

Diels-Alder reaction between indoles and cyclohexadienes photocatalyzed by a (thia)pyrylium salt

María González BéjarSalah Eddine StiribaJulia Pérez Prieto

subject

Indoles 1.3-cyclohexadienesUNESCO::QUÍMICA:QUÍMICA::Química orgánica [UNESCO]Diels-Alder reaction ; Photocatalysis ; Thiapyrylium salts ; Indoles 1.3-cyclohexadienesUNESCO::QUÍMICA::Química orgánicaPhotocatalysisDiels-Alder reaction:QUÍMICA [UNESCO]Thiapyrylium salts

description

"Thiapyrylium salt 1 is an efficient photocatalyst in the Diels-Alder reaction between indoles (InHs) and 1,3-cyclohexadienes (CHDs). For instance, irradiation of deaerated dichloromethane solutions containing 1 (1 mM), indole (20 mM) and cyclohexadiene (40 mM), in the presence of an acylating agent, led to the Diels-Alder cycloadduct in 62% yield (endo:exo ratio of 1.8:1). Taking into account the very high intersystem crossing yield (Φisc = 0.97) of thiapyrylium salt 1, involvement of its triplet excited state in this Diels-Alder reaction has been studied using steadystate and time-resolved experiments; the results are compared with those previously obtained for pyrylium salts, which exhibit a considerable fluorescence quantum yield and are assumed to operate via electron transfer from the InH to their singlet excited state." Gonzalez Bejar, Maria, Maria.Gonzalez@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es

http://hdl.handle.net/10550/12892