Enantioselective alkynylation and phenylation of aromatic aldehydes promoted by atropisomeric 1,1’-binaphthylazepine-based aminoalcohols

The atropisomeric 1,1-binaphthylazepine-based 1,2-amino alcohols 1b and 1c were tested as catalysts in the enantioselective addition of zinc phenylacetylide and diphenylzinc to aromatic aldehydes in order to achieve, respectively, optically active propargyl alcohols and diarylcarbinols. In both these reactions, ligand 1c proved to be more efficient than 1b, affording ees up to 70% in the addition of phenylacetylene to arylaldehydes and ees up to 54% in the diphenylzinc addition.