Rh(I)-Catalyzed Enantioselective Hydrogenation of α-Substituted Ethenylphosphonic Acids
作者:Kaiwu Dong、Zheng Wang、Kuiling Ding
DOI:10.1021/ja305780z
日期:2012.8.1
A class of chiral Rh(I) catalysts containing monodentate phosphorous aciddiesters tautomerized from the corresponding secondary phosphine oxides was discovered by serendipitous hydrolysis of phosphoramidite ligands. The evolved catalysts demonstrated unprecedented enantioselectivities (98-99% ee) and high catalytic activities (as low as 0.01 mol% catalyst loading) in asymmetric hydrogenations of a
作者:N. S. Gulyukina、A. V. Varakuta、I. P. Beletskaya
DOI:10.1007/s11172-007-0290-y
日期:2007.9
A simple method for the synthesis of 1-arylcyclopropylphosphonates was proposed. The method involves treatment of 1-arylethenylphosphonic acids or their esters with diazomethane followed by thermolysis of intermediate 3-aryl-4,5-dihydro-3H-pyrazol-3-ylphosphonates.
The first asymmetrichydrogenation of vinylphosphonic acids and esters to the corresponding arylethylphosphonic acids and esters using chiralRu(II) catalysts is reported with enantiomeric excesses up to 86%.
Efficient Ni/(S,S)-Ph-BPE-catalyzed asymmetrichydrogenation of α-substituted α,β-unsaturated phosphine oxides/phosphonates/phosphoric acids has been successfully developed, and a wide range of chiral α-substituted phosphines hydrogenation products were obtained in generally high yields with excellent enantioselective control (92%–99% yields, 84%−>99% ee). This method features a cheap transition metal
成功开发了Ni/( S , S )-Ph-BPE催化的α-取代α,β-不饱和膦氧化物/膦酸酯/磷酸的高效不对称加氢反应,并获得了多种手性α-取代膦加氢产物获得普遍高产率和出色的对映选择性控制(92%–99% 产率,84%−>99% ee)。该方法具有廉价的过渡金属镍催化体系、高官能团耐受性、广泛的底物范围通用性和优异的对映选择性。根据氘标记实验的结果,为这种不对称氢化提出了一个似是而非的催化循环。
Enantioselective Synthesis of Chiral α-Aryl or α-Alkyl Substituted Ethylphosphonates via Rh-Catalyzed Asymmetric Hydrogenation with a <i>P</i>-Stereogenic BoPhoz-Type Ligand
An enantioselective synthesis of optically active 1-aryl or 1-alkyl substituted ethylphosphonates, based on the first Rh-catalyzed asymmetric hydrogenation of corresponding alpha,beta-unsaturated precursors with a P-stereogenic BoPhoz-type ligand under the mild condition, was developed, in which a wide range of 1-aryl or 1-alkyl substituted ethylphosphonates were achieved in up to 98% ee.