Organocatalyzed Intramolecular Carbonyl-Ene Reactions

Abstract

An organocatalyzed intramolecular carbonyl-ene reaction was developed to produce carbocyclic and heterocyclic 5- and 6-membered rings from a citronellal-derived trifluoroketone and a variety of aldehydes. A phosphoramide derivative was found to promote the cyclization of the trifluoroketone, whereas a less acidic phosphoric acid proved to be a superior catalyst for the aldehyde substrates.

Keywords

• organocatalysis
• carbonyl-ene
• phosphoric acid
• N-triflylphosphoramide