Total synthesis of PDE-I and -II by copper-mediated double aryl amination This paper is dedicated to Professor Teruaki Mukaiyama in celebration of the 40th anniversary of the Mukaiyama aldol reaction

A concise total synthesis of PDE-I and -II featuring copper-mediated double aryl amination with the combination of CuI, CsOAc, and Cs₂CO ₃ is described. The highly substituted pyrroloindole skeleton was constructed by a one-pot five-step sequence including double aryl amination, β-elimination, deprotection of a Cbz group, and unexpected formation of an indole via removal of an Ns group followed by rearomatization. The undesired elimination of the protecting group (Ns group) was hampered by using the Boc group as a protecting group in the second-generation synthesis, which excluded the reduction of the indole required in the first-generation synthesis.