134015-45-5Relevant academic research and scientific papers
Enantioselective nickel-catalyzed conjugate addition of dialkylzinc to chalcones using chiral α-amino amides
Escorihuela, Jorge,Burguete, M. Isabel,Luis, Santiago V.
scheme or table, p. 6885 - 6888 (2009/04/07)
A series of α-amino amides derived from natural amino acids (alanine, valine, phenylalanine, isoleucine, and phenylglycine) have been synthesized and fully characterized. Their Ni(II) complexes prepared from Ni(acac)2 catalyze the enantioselective conjugate addition of diethylzinc to chalcones in high yields and in good enantioselectivities (up to 84%). The side chain of the amino acid and the substituents in the amide nitrogen govern the enantioselectivity of the catalytic process.
Proline-based dipeptides with two amide units as organocatalyst for the asymmetric aldol reaction of cyclohexanone with aldehydes
Chen, Fubin,Huang, Shi,Zhang, Hui,Liu, Fengying,Peng, Yungui
, p. 9585 - 9591 (2008/12/22)
A series of proline-based dipeptide organocatalysts with two amide units (1-16) have been developed and evaluated in the direct catalytic asymmetric aldol reactions of aldehydes with cyclohexanone. These catalysts showed good solubility in organic solvents compared with their corresponding carboxyl terminal dipeptides. The robust amide bond formation allowed structural modifications and fine tuning of catalyst properties by varying the stereo and electronic effects of the terminal amide to affect the ability of hydrogen bonding formation between the catalysts and the substrates. The reactions proceeded smoothly in high yields (up to 99%), enantioselectivities (up to 98% ee) and anti-diastereoselectivities (up to 99:1) in the presence of bifunctional organocatalyst 4 under the optimal reaction conditions.
