作者:Yasmin Brinkmann、Reniguntala J. Madhushaw、Rodolphe Jazzar、Gerald Bernardinelli、E. Peter Kündig
DOI:10.1016/j.tet.2007.06.033
日期:2007.8
(acetone)(R,R)-BIPHOP-F)Cp][SbF6], a transition metal Lewis acid that catalyzes the [3+2] dipolar cycloaddition reaction between aryl nitrile oxides and α,β-unsaturated aldehydes to give chiral 2-isoxazolines with yields of 43–98% and asymmetric purity of 60–93% ee. The stereochemistry of the major enantiomer is S, consistent with an approach of the nitrile oxide to the Cα-Si face of the enal in the anti-s-trans
详细描述了手性配体(R,R)-BIPHOP-F的合成。它与阳离子环戊二烯基钌片段的配位产生[Ru(丙酮)(R,R)-BIPHOP-F)Cp] [SbF 6 ],一种过渡金属路易斯酸,催化芳基腈之间的[3 + 2]双极环加成反应。氧化物和α,β-不饱和醛可制得手性2-异恶唑啉,产率为43–98%,ee的不对称纯度为60–93%ee。的主要对映体的立体化学是小号,与氧化腈的方式的方式相一致Ç α -硅在烯醛的面抗-小号-反式 催化剂部位的构象。