Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
J Am Chem Soc. 2009 Mar 11;131(9):3122-3. doi: 10.1021/ja809873u.
A highly diastereoselective dynamic kinetic asymmetric transformation of racemic 1,1-cyclopropane diesters to prepare enantioenriched tetrahydrofuran (THF) derivatives has been developed. Asymmetric [3 + 2] cycloaddition of activated donor-acceptor (D-A) cyclopropanes and aldehydes catalyzed by ((t)Bu-pybox)MgI(2) gives THF products in good to excellent yields (48-92%) as single diastereomers with er's up to 97:3. Aryl, cinnamyl, and aliphatic aldehydes are competent dipolarophiles for this transformation.
已开发出一种高对映选择性的动态动力学非对映转化方法，用于将外消旋 1,1-环丙烷二酯转化为手性富集的四氢呋喃（THF）衍生物。（tBu-pybox）MgI2 催化的活化给体-受体（D-A）环丙烷与醛的不对称[3+2]环加成反应以高至 97:3 的对映过量值（er）作为单一非对映异构体，以良好至优异的收率（48-92%）得到 THF 产物。芳基、肉桂基和脂肪醛是该转化的合适偶极子。
