General One-pot, Two-Step Protocol Accessing a Range of Novel Polycyclic Heterocycles with High Skeletal Diversity

An Ugi one-pot three-component four-center reaction was
coupled
with a subsequent acid mediated cyclodehydration step to furnish a
multitude of unique scaffolds having in common an embedded or attached
benzimidazole and often a ring system formed through lactamization.
Using combinations of tethered Ugi inputs typically via tethered acid-ketone
inputs and supporting reagents containing masked internal nucleophiles,
such scaffolds were produced in good to excellent yields in an operationally
friendly manner.