Scandium‐Triflate‐Catalyzed Regioselective Ring Opening of Purines with Aminocyclopropanes

An efficient route to acyclic purine nucleoside analogues with an amino group at the C1′ position of the side chains has been reported. Using Sc(OTf) 3 as the catalyst, the ring‐opening reaction of purines with aminocyclopropanes afforded acyclic nucleoside analogues with moderate to good yields and in a regioselective manner. Furthermore, phenyl cyclopropane also gave the desired acyclic nucleoside analogue with a phenyl linked at C1′ position. Furthermore, generation of a penciclovir analogue may also occur from the ring‐opening product via a reduction reaction.