Chemistry - Hydrocarbon Question with Solution | TestHub

The decreasing order for electrophilic substitution reaction is as Pyrrole > Furan > Thiophene.
Degree of reactivity depends on electron availability or electron donating power of the hetero atom of the ring. In thiophene lone of S is delocalised by the ring as well as by the vacant d-orbitals. Hence electron donating power of S is least.