Synthesis of Novel C
2 Bishydroxamic Acid Ligands and their Application in Asymmetric Epoxidation Reactions
作者:José L. Olivares-Romero、Tushar Janardan Pawar、Marco F. Valtierra-Galvan、Alfredo Rodríguez-Hernández、Alfonso Reyes-Luna、Israel Bonilla-Landa、Oscar García-Barradas、Felipe Barrera-Méndez
DOI:10.1055/s-0042-1751481
日期:2023.12
Asymmetric oxidation reactions have significantly benefited from bishydroxamic Brønsted acid ligands, and they can proceed with remarkable stereoselectivity. Designing and synthesizing these ligands are essential for achieving high enantioselectivity in metal-catalyzed oxidation reactions. This paper presents a straightforward method for synthesizing novel phenyl-ring-centric bishydroxamic acids (BHA). A preliminary
作者:Deborah A. Smithen、Christopher J. Mathews、Nicholas C. O. Tomkinson
DOI:10.1039/c2ob25293g
日期:——
Reaction of cyclic ketones with chiral N-alkyl-O-acyl hydroxylamines leads to the corresponding α-oxyacylated carbonyl compound in up to 89% ee. The levels of asymmetric induction were influenced by solvent polarity, acid strength and, to a lesser extent, temperature. Increasing the steric bulk around the nitrogen atom of the hydroxylamine reagent led to increased levels of asymmetric induction, which was also found to be detrimental to the yield observed for the transformation. Examination of N- and O-substituents along with substrates revealed the scope and limitations of the procedure.