Application of heterocyclic aldehydes as components in Ugi–Smiles couplings

• Katelynn M. Mason,
• Michael S. Meyers,
• Abbie M. Fox and
• Sarah B. Luesse

Beilstein J. Org. Chem. 2016, 12, 2032–2037, doi:10.3762/bjoc.12.191

• also a competent component for Ugi–Smiles adduct formation. Keywords: Diels–Alder cycloaddition; epoxyisoindoline; multicomponent coupling reaction; tandem reaction; Ugi–Smiles coupling; Introduction Synthetic methods to efficiently prepare libraries of biologically-relevant compounds are in demand

• reactants for the four-component Ugi–Smiles coupling [21]. A notable exception is one reported example of 2-furaldehyde participating in a Ti(O-iPr)4-catalyzed modified Ugi–Smiles reaction that used an isocyanide as an amine equivalent [22]. We recently reported a successful tandem Ugi–Smiles intramolecular

• -furaldehyde supported our understanding of the observed tandem US-IMDA reaction with allylamine as an Ugi–Smiles coupling followed by an intramolecular cyclization. We were interested in exploring the reaction pathway in an effort to improve reaction conversion. As Ugi–Smiles products had not been isolated