No, it is not permissible. It is like praying behind a christian or jew. The shee`ah, who are mostly from the rawaafidh, are kuffaar and out of the fold of Islaam.
:salam2:
It is not allowed to pray behind shia ,as they hold a different meaning of oneness.Praying behind a person holding a kufr aqeedah is not allowed.Same goes for an innovator.