Palladium-catalyzed, asymmetric Baeyer–Villiger oxidation of prochiral cyclobutanones with PHOX ligands
作者:Kimberly S. Petersen、Brian M. Stoltz
DOI:10.1016/j.tet.2011.04.046
日期:2011.6
method for the conversion of prochiral 3-substituted cyclobutanones to enantioenriched γ-lactones through a palladium-catalyzed Baeyer–Villiger oxidation using phosphinooxazoline ligands in up to 99% yield and 81% ee. Lactones of enantiopurity ≥93% could be obtained through a single recrystallization step. Importantly, 3,3-disubtituted cyclobutanones produced enantioenriched lactones containing a β-quaternary
本报告介绍了一种通用方法,该方法通过使用膦氧恶唑啉配体的钯催化的Baeyer-Villiger氧化,将前手性3取代的环丁酮转化为对映体富集的γ-内酯,产率高达99%,ee高达81%。对映纯度≥93%的内酯可通过一个重结晶步骤获得。重要的是,3,3-二取代的环丁酮产生了富含β-季中心的对映体富集的内酯。