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.
环酮与手性N-烷基-O-酰基羟胺的反应可生成相应的α-氧酰基羰基化合物,其对映体过量率达89%。不对称诱导的水平受到溶剂极性、酸强度以及温度(影响较小)的影响。增加羟胺试剂中氮原子周围的立体障碍,可提高不对称诱导的水平,但这也会对转化反应的产率产生不利影响。通过对N-和O-取代基以及底物的考察,揭示了该方法的应用范围和局限性。