Organocatalytic Enantioselective Conjugate Alkynylation of ß-Aminoenones: Access to Chiral ß-Alkynyl-ß-Amino Carbonyl Derivatives.

ABSTRACT

Readily available potassium alkynyltrifluoroborates were used for organocatalytic asymmetric conjugate alkynylation of ß-enaminones. The interception of a modified binaphthol catalyst and in situ generated organodifluoroboranes proved important to access functionalized ß-alkynyl-ß-amino carbonyls and derivatives with improved chemo-reactivity and enantio-induction. Mechanistic studies revealed the impact of molecular sieves on efficiency and stereocontrol. The products undergo additional functionalization to yield a diverse set of valuable ß-alkynyl-ß-amino carbonyl scaffolds.