制备了具有双氢电位的脯氨酰胺,并将其用作不对称羟醛反应的有机催化剂。含有金刚烷的催化剂显示出改进的催化活性,通过使用盐水作为溶剂进一步增强了催化活性。在 0 °C 的盐水中进行的一系列羟醛反应提供了良好的产率(高达 98%)以及高非对映选择性(>99:1)和对映选择性(>99%)。制备的催化剂在反应体系中通过主客体相互作用被聚(AN-MA-β-CD)纳米纤维膜吸附。通过超声波将催化剂从薄膜中分离出来,总回收率为96.2%。该催化剂可重复使用五次,非对映选择性和对映选择性没有显着变化。
Proline dipeptides containing fluorine moieties as oganocatalysts for the asymmetric aldol reaction
作者:Ardiol Ahmetlli、Nikoleta Spiliopoulou、Angeliki Magi-Oikonomopoulou、Dimitrios-Triantaffylos Gerokonstantis、Panagiota Moutevelis-Minakakis、Christoforos G. Kokotos
DOI:10.1016/j.tet.2018.08.038
日期:2018.10
demonstrated, where aromaticaldehydes afforded products in high yields (up to 100%) with excellent diastereo- (up to 95:5) and enantioselectivities (up to 97%), whereas the aliphaticaldehydes afforded also excellent selectivities, but relatively low yield. A simple addition of fluorine to a dipeptide analogue affords organocatalysts with new interesting properties that can catalyze the aldol reaction
Synthesis and Characterization of Monosaccharide Derivatives and Application of Sugar-Based Prolinamides in Asymmetric Synthesis
作者:Jyoti Agarwal、Rama Krishna Peddinti
DOI:10.1002/ejoc.201200522
日期:2012.11
were converted into the corresponding prolinamide organocatalysts (i.e., 1a, 2a, 3a, and 3b) in high yields. The catalytic activity of these sugar-based prolinamide organocatalysts was demonstrated in asymmetric aldol reactions in various solvents and at different temperatures. The oraganocatalyst 3a was shown to be an efficient and powerful organocatalyst for the enantioselective aldol reaction of various
Different bio/Lewis acid-catalyzed stereoselective aldol reactions in various mediums
作者:Tülay Yıldız、Hasniye Yaşa、Belma Hasdemir、Ayşe S. Yusufoğlu
DOI:10.1007/s00706-017-1967-z
日期:2017.8
Brønsted acids were used for asymmetric aldol reactions of aromatic, heteroaromatic, cyclic, and acyclic six ketones and eleven aldehydes. Optimum reaction conditions were determined by changing temperature and enzyme, ketone, aldehyde, solvent, cofactors types, amounts, and ratios. PPL (porcine pancreatic lipase) of animal and AL-AN (amano lipase A from Aspergillus niger) of fungal origins were the
Evaluation of Amino Nitriles and an Amino Imidate as Organocatalysts in Aldol Reactions
作者:Nikolaos Vagkidis、Alexander J. Brown、Paul A. Clarke
DOI:10.1055/s-0039-1690150
日期:2019.11
and a tert-butyl l-proline imidate as organocatalysts for the aldolreaction have been evaluated. l-Valine nitrile was found to be a syn-selective catalyst, while l-proline nitrile was found to be anti-selective, and gave products in modest to good enantioselectivities. tert-Butyl l-proline imidate was found to be a very efficient catalyst in terms of conversion of starting reagents to products, and
A chemo-enzymatic oxidation/aldol sequential process directly converts arylbenzyl alcohols and cyclohexanol into chiral β-hydroxy carbonyls
作者:Yu Wang、Chengyi Wang、Qipeng Cheng、Yu Su、Hongyu Li、Rui Xiao、Chunxia Tan、Guohua Liu
DOI:10.1039/d1gc02831f
日期:——
transformation, an initial laccase-mediated oxidation of arylbenzyl alcohols and cyclohexanol to form aldehydes and cyclohexanone, followed by a subsequent proline derivative-catalyzed aldol condensation of the in situ generated intermediates, provides various 1,2-diastereoisomeric chiral β-hydroxy ketones with acceptable yields and high enantio-/diastereoselectivities.