Synthesis of Tetracyclic Molecules Containing Medium-Sized Heterocycles: Scope Expansion of Cascade Nicholas and Pauson–Khand Methodology

Abstract

Unique tetracyclic molecules containing heteroatom-embedded, medium-sized rings were synthesized by employing cascade Nicholas and Pauson–Khand cyclization reactions. We successfully established a divergent synthetic route for quick access to unprecedented multi-ring systems via an alkyne cobalt complex, and an expanded substrate scope for this methodology was realized.