Efficient π-Facial Control in the Ene Reaction of Nitrosoarene, Triazolinedione, and Singlet Oxygen with Tiglic Amides of the Bornane-Derived Sultam as Chiral Auxiliary: An Economical Synthesis of Enantiomerically Pure Nitrogen- and Oxygen-Functionalized Acrylic Acid Derivatives
作者:Waldemar Adam、Hans-Georg Degen、Oliver Krebs、Chantu R. Saha-Möller
DOI:10.1021/ja026640e
日期:2002.11.1
The ene reaction of 4-nitronitrosobenzene (ArNO), N-phenyl-1,2,4-triazoline-3,5-dione (PTAD), and singlet oxygen (1O2) with the optically active tiglic-acid derivatives of Oppolzer's bornane-derived sultam affords the respective ene products regioselectively in excellent diastereoselectivity (de up to 99%) and in good yield (55-90%). The enophiles ArNO and PTAD give with the methyl-substituted substrate
4-亚硝基苯 (ArNO)、N-苯基-1,2,4-三唑啉-3,5-二酮 (PTAD) 和单线态氧 (1O2) 与 Oppolzer 冰片的旋光性tiglic-酸衍生物的烯反应-衍生的 sultam 以优异的非对映选择性(de 高达 99%)和良好的产率(55-90%)区域选择性地提供了相应的烯产物。亲烯体 ArNO 和 PTAD 与甲基取代的底物仅产生类似构型的烯加合物,而 1O2 产生 83:17 的非对映体混合物。对于空间上要求更高的异丙基取代衍生物,即使是最小的亲烯体 1O2 也只能形成类似的非对映异构体。高非对映选择性在底物的适当构象排列和来自双键的 C(β)-re 面的优选亲烯攻击方面被合理化。