Total synthesis of PDE-II by copper-mediated double amination.

A concise total synthesis of PDE-II featuring copper-mediated double aryl amination with the combination of CuI, CsOAc, and Cs2CO3 is described. The highly substituted pyrroloindole skeleton was constructed by a one-pot five-step sequence including double aryl amination, beta-elimination, deprotection of a Cbz group, and removal of an Ns group followed by rearomatization.