“Chemzyme” for Carbonyl-Ene Reactions

Organocatalyzed Intramolecular Carbonyl-Ene Reactions.

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.

Enantioselective syn-selective scandium-catalyzed ene reactions.

An enantio- and diastereoselective carbonyl-ene reaction catalyzed by chiral scandium pyridyl bis(oxazoline) (pybox) complexes has been developed. Uniformly high enantiomeric excesses and good yields were observed. Use of trisubstituted olefins generated the syn product in high enantio- and diastereoselectivity.

Catalytic Conia-ene and related reactions.

Since its initial inception, the Conia-ene reaction, known as the intramolecular addition of enols to alkynes or alkenes, has experienced a tremendous development and appealing catalytic protocols have emerged. This review fathoms the underlying mechanistic principles rationalizing how substrate design, substrate activation, and the nature of the catalyst work hand in hand for the efficient syn...

Fluorescent pyrrole products from carbonyl-amine reactions.

The reaction of (E)-4,5-epoxy-(E)-2-heptenal with butylamine and glycine methyl ester produced brown macromolecular pigments, which showed fluorescent characteristics similar to lipofuscins. This polymerization reaction implies in the first step the formation of 1-alkyl-2-(1'-hydroxyalkyl)pyrroles (IV, VI). Compounds IV and VI have been isolated and characterized from the above reactions, and t...

Organic reactions catalyzed by rhenium carbonyl complexes.