Synthesis of a New Chiral <i>N,N,N</i>-Tridentate Pyridinebisimidazoline Ligand Library and Its Application in Ru-Catalyzed Asymmetric Epoxidation
作者:Santosh Bhor、Gopinathan Anilkumar、Man Kin Tse、Markus Klawonn、Christian Döbler、Bianca Bitterlich、Anne Grotevendt、Matthias Beller
DOI:10.1021/ol050821e
日期:2005.8.1
A small ligand library of chiral tridentate N,N,N-pyridinebisimidazolines have been synthesized for the first time. This new class of ligands can be easily tuned and synthesized on multi g-scale. The usefulness of the ligands is shown in the ruthenium-catalyzed asymmetric epoxidation with hydrogen peroxide as oxidant. Excellent yields (>99%) and good enantioselectivities (up to 71% ee) have been obtained
首次合成了手性三齿N,N,N-吡啶双咪唑啉的小型配体库。这类新型的配体可以很容易地在多g级上调节和合成。配体的有用性在用过氧化氢作为氧化剂的钌催化的不对称环氧化中显示。对于芳族烯烃的环氧化,已经获得了优异的收率(> 99%)和良好的对映选择性(最高71%ee)。[反应:看文字]