Simple and inexpensive threonine-based organocatalysts as highly active and recoverable catalysts for large-scale asymmetric direct stoichiometric aldol reactions on water
作者:Chuanlong Wu、Xiaoqin Long、Shi Li、Xiangkai Fu
DOI:10.1016/j.tetasy.2012.02.023
日期:2012.3
direct asymmetric stoichiometric aldolreaction on water by using variable amounts of water. These threonine-based organocatalyst were simple, inexpensive, highly active and could be synthesized on a large-scale. Among them, the threonine-based organocatalyst 1a is applicable to the stoichiometric reactions of a wide range of aromatic and heteroaromatic aldehydes with ketones, with the aldol products
The intermolecular reductive coupling reaction of cyclopent-2-enone and aromatic aldehydes was realized by chiral rhodium-(bisoxazolinyl)phenyl catalysts, Rh(Phebox-Ph)(OAc)(2)(H2O), with diphenymethylsilane as a hydride donor to give the corresponding beta-hydroxyketones in high anti selectivity (up to 96%) with high enantioselectivity (up to 93%).
Both Amide-Bearing α- and β-Amino Acids from Natural Aspartic Acid Are Efficient Organocatalysts for Enantioselective Aldol Reactions
作者:Gen-Fa Wen、Rui Zhang、Chao-Shan Da、Chu-Yu Zhang
DOI:10.1055/a-1953-1656
日期:2023.2
of structurally similar α- and β-amino acids in an asymmetric aldol transformation. Interestingly, aspartic acid is not only an α-amino acid, but also a β-amino acid. Thus, by modifying one of the two acidic groups of aspartic acid, two sets of α- and β-amino acids, 14 amino acids in total, were prepared and used as organocatalysts. The two types of amino acid, interestingly, achieved similar high catalytic