Osberger Thomas J, White M Christina
Roger Adams Laboratory, University of Illinois Urbana-Champaign , Champaign, Illinois 61801, United States.
J Am Chem Soc. 2014 Aug 6;136(31):11176-81. doi: 10.1021/ja506036q. Epub 2014 Jul 24.
A Pd(II)/bis-sulfoxide/Brønsted acid catalyzed allylic C-H oxidation reaction for the synthesis of oxazolidinones from simple N-Boc amines is reported. A range of oxazolidinones are furnished in good yields (avg 63%) and excellent diastereoselectivities (avg 15:1) to furnish products regioisomeric from those previously obtained using allylic C-H amination reactions. Mechanistic studies suggest the role of the phosphoric acid is to furnish a Pd(II)bis-sulfoxide phosphate catalyst that promotes allylic C-H cleavage and π-allylPd functionalization with a weak, aprotic oxygen nucleophile and to assist in catalyst regeneration.
报道了一种钯(II)/双亚砜/布朗斯特酸催化的烯丙基C-H氧化反应,用于从简单的N-叔丁氧羰基胺合成恶唑烷酮。一系列恶唑烷酮以良好的产率(平均63%)和优异的非对映选择性(平均15:1)得到,产物的区域异构体与之前使用烯丙基C-H胺化反应得到的不同。机理研究表明,磷酸的作用是提供一种钯(II)双亚砜磷酸盐催化剂,该催化剂促进烯丙基C-H裂解和与弱的非质子氧亲核试剂进行π-烯丙基钯官能化,并协助催化剂再生。