N-Heterocyclic Carbene-Mediated Enantioselective Addition of Phenols to Unsymmetrical Alkylarylketenes
作者:Carmen Concellón、Nicolas Duguet、Andrewâ
D. Smith
DOI:10.1002/adsc.200900538
日期:2009.11
Chiral N-heterocyclic carbenes (NHCs) mediate the enantioselective addition of 2-phenylphenol to unsymmetrical alkylarylketenes, delivering α-alkyl-α-arylacetic acid derivatives with good levels of enantiocontrol (up to 84% ee). Enantiodivergent stereochemical outcomes are observed using 2-phenylphenol and benzhydrol in the NHC-promoted esterification reaction using a triazolium precatalyst derived
手性N-杂环卡宾(NHC)介导将2-苯基苯酚对映选择性加成到不对称的烷基芳基烯酮中,从而提供具有良好对映体控制水平的ee-烷基-α-芳酸衍生物(最高ee达84%)。在NHC促进的酯化反应中使用2-苯基苯酚和二氢苯酚,使用衍生自焦谷氨酸的三唑鎓预催化剂观察到对映体立体化学结果,这与这些过程中起作用的独特机理相符。