首次,通过使用咪唑鎓离子束缚的TsDPENs作为铱在水中α-酮膦酸酯的铱催化的不对称转移氢化(ATH)的有效配体,开发了一种有效的方法。该反应在不添加任何表面活性剂的条件下,在温和的反应条件下,以中等至良好的收率(44-78%)和良好至出色的对映选择性(高达> 99%ee)提供了所需的产物α-羟基膦酸酯。通过使用(-)-金可尼定作为手性溶剂化剂,通过13 P NMR测定对映体过量,这是一种比手性HPLC更方便的方法。
A novel manganese/proline-derived catalyst system is reported for the stereoselective synthesis of α-hydroxyphosphonates and α-aminophosphonates. The reaction proceeded smoothly under mild reaction conditions with efficient reaction times. The resulting products were obtained with high yields and good enantioselectivities (up to 83% ee).
Asymmetric Hydrogenation of α-Keto Phosphonates with Chiral Palladium Catalysts
作者:Nataliya S. Goulioukina、Grigorii N. Bondarenko、Alexei V. Bogdanov、Konstantin N. Gavrilov、Irina P. Beletskaya
DOI:10.1002/ejoc.200800943
日期:2009.2
Under atmospheric hydrogen pressure, a catalytic amount of palladium(II) trifluoroacetate and (R)-MeO-BIPHEP in 2,2,2-trifluoroethanol promoted the asymmetrichydrogenation of diisopropyl α-ketophosphonates 1 to afford the corresponding α-hydroxy phosphonates 2 in excellent yields and with a moderate enantioselectivities of up to 55 % ee. Racemic α-aryl-α-hydroxy phosphonates can be prepared by using
1,1′-Dibenzyl-bis-(triazolyl)diphenylphosphine dioxide: a new efficient organocatalyst for silicon tetrachloride-mediated enantioselective Abramov-type phosphonylation of aldehydes with trialkyl phosphites
Asymmetric phosphonylation of aldehydes with trialkylphosphites using a combination of SiCl4 and a novel 1,1′-dibenzyl-bis-(triazolyl)diphenylphosphine dioxide organocatalyst has been developed. This protocol provides the corresponding α-hydroxyphosphonates with a broad range of functional groups and substitution patterns in excellent yields and good selectivities.