Diastereoselective Synthesis of High Functionalized 4‐Imidazolidinone‐Tetrahydro‐β‐Carboline Hybrids via Divergent Post‐Ugi Transformation

Abstract

An easily scalable and highly diastereoselective synthesis of challenging 1,2,5,6,11,11b‐hexahydro‐3H‐imidazo[1',2':1,2]pyrido[3,4‐b]indol‐3‐ones is accomplished through divergent transformation of Ugi 4‐CR products. The trimethylsilyl trifluoromethanesulfonate (TMSOTf) mediated intramolecular condensation of a series of Ugi 4‐CR adducts generates a N‐acylimidinium intermediate which undergoes ring closure to selectively afford the target title compounds in good to high yields.