Microwave-Assisted Michael Addition of Some Pyrimidine and Purine Nucleobases with α,β-Unsaturated Esters: A Rapid Entry into Carboacyclic Nucleoside Synthesis - Khalafi-Nezhad, A; Zarea, A; Soltani Rad, M N; Mokhtari, B; Parhami, A (Synthesis, 2005)