由手性膦BINAP容易制备的手性膦氧化物BINAPO在三氯甲硅烷基化合物通过高价硅酸盐中间体的反应中表现出良好的催化活性。在催化量的BINAPO存在下,醛与烯丙基三氯硅烷的烯丙基化反应使烯丙基化的加合物具有良好的对映选择性(最高79%ee),其中二异丙基乙胺和四丁基碘化铵作为添加剂的组合对于加速催化循环至关重要。31氧化膦的1 P NMR分析表明,胺促进了氧化膦从硅原子上的解离。BINAPO还促进了二异丙基乙胺作为添加剂存在下醛与三氯甲硅烷基烯醇醚的对映体选择性醛醇缩合反应,从而以高非对映体和对映体选择性(最高syn / anti = 1 / 25,96%ee(anti))提供了相应的醛醇加合物。)。
water-compatible proline catalysts (4–6) derived from calixarene bearing a hydrophobic nature have been synthesised. It was found that the compound 4 was a highly efficient organocatalyst for aldol reactions occurred in the water. Under optimised reaction conditions, high yields (up to 82%), good enantioselectivities (ee up to 81%) and high diastereoselectivities (dr up to 91:9) were obtained.
Prolinamides of Aminouracils, Organocatalyst Modifiable by Complementary Modules
作者:Karen M. Ruíz-Pérez、Beatriz Quiroz-García、Marcos Hernández-Rodríguez
DOI:10.1002/ejoc.201800886
日期:2018.11.8
Prolinamide organocatalysts with aminouracils have the features of enhanced NH acidity, an additional hydrogen‐bond donor and the self‐assembly with complementary modules by Watson–Crick pairing. Each module affects the selectivity of the reaction and particularly 2,6‐diaminopyridine is beneficial to the selectivity in the reaction.
Oxazoline-Substituted Prolinamide-Based Organocatalysts for the Direct Intermolecular Aldol Reaction between Cyclohexanone and Aromatic Aldehydes
作者:Simon Doherty、Julian G. Knight、Amy McRae、Ross W. Harrington、William Clegg
DOI:10.1002/ejoc.200700922
日期:2008.4
Oxazoline-substituted prolinamides catalyse the direct asymmetric aldol reaction between cyclohexanone and a range of aldehydes to give excellent conversions and enantioselectivities up to 84 % under optimum conditions. Reactions were highly substrate-specific with electron-deficient aldehydes giving the highest yields and ee values. The absolute configuration of the 4-chlorobenzaldehyde-derived product
Highly efficient organocatalysts for the asymmetric aldol reaction
作者:C. G. Jacoby、P. H. V. Vontobel、M. F. Bach、P. H. Schneider
DOI:10.1039/c7nj04424k
日期:——
synthetic route. The highly efficient five step methodology did not require intermediary purification and provided the compounds in high yields. The catalysts were successfully applied in the asymmetric direct aldolreaction between aromatic aldehydes and cyclic ketones in aqueous media. Aldol adducts were obtained in high yields with perfect stereoselectivities (up to >99% e.e. and >19 : 1 d.r.).
successfully used as a cocatalyst for L-proline catalyzed aldolreactions in the presence of water. The anticonfigured products were obtained with good yields (up to 94%), high diastereoselectivities (up to 95:5), and high enantiomeric excesses (up to 93% ee ). The successful results for catalytic efficiency of L-proline in the presence of water reveal the importance of the hydrophobic nature of cholesterol