Electrophilic Substitutions of Five-Membered Rings

摘要: Publisher Summary The chapter attempts to provide a sufficiently complete summary of all the quantitative and semiquantitative information available concerning electrophilic substitution in five-membered heteroaromatic rings. is organized following manner. After preliminary introduction “aromaticity” rings, discussion centered mainly on process itself, mechanism various substitutions considered separately. Afterward attention shifted from electrophile substrate, relative reactivity different rings ring positions widely examined. Finally, problem transmission electronic effects substituents across these application Kammett-type correlations discussed. Systems are parent heterocycles with one heteroatom (furan, thiophene, selenophene, pyrrole), their monoaza polyaza derivatives, monobenzo derivatives above systems. General surveys chemistry furan,l thiophene,2 pyrrle, benz∼thiophene, an d selenophene4 have been published recent years; reference made them, whenever necessary.