Concise synthesis and transannular inverse electron demand Diels-Alder reaction of [3](3,6)pyridazino[3](1,3)indolophane. Rapid access to a pentacyclic indoloid system

GRAPHICS The title compound was synthesized concisely from indole. A 2-fold sequential hydroboration/Suzuki-Miyaura cross-coupling was employed to generate the cyclophane. When heated in N,N-diethylaniline, it underwent a transannular inverse electron demand Diels-Alder (IEDDA) reaction to form a pentacyclic product, which appears to be well suited as a precursor to a variety of indole alkaloids such as strychnine.