Highly Enantioselective Direct syn- and anti-Aldol Reactions of Dihydroxyacetones Catalyzed by Chiral Primary Amine Catalysts
摘要:
We present herein simple primary-tertiary diamine-Bronsted acid conjugates that catalyze both syn- and anti-adol reactions of dihydroxyacetones (DHAs) with high diastereoselectivities and enantioselectivities. This type of organocatalysts functionally mimics all four DHA aldolases, namely L-fuculose-1-phosphate aldolase, D-tagatose-1,6-diphosphate aldolase, D-fructose-1,6-diphosphate aldolase, and L-rhamnulose-1-phosphate aldolase.
Pepsin-catalyzed direct asymmetric aldol reactions for the synthesis of vicinal diol compounds
作者:Ling-Yu Li、Da-Cheng Yang、Zhi Guan、Yan-Hong He
DOI:10.1016/j.tet.2015.01.061
日期:2015.3
The catalytic promiscuity of pepsin from porcine gastric mucous was observed in catalysis of the direct asymmetric aldol reactions of aromaticaldehydes with acetones, which were substituted by hydroxy-, dihydroxy-, methoxy- and benzyloxy- for the synthesis of diol compounds in acetonitrile. This biocatalysis was also applicable to the aldol reactions of cyclic or hetereocyclic ketones with aromatic
A phosphotungstic acid-supported multifunctional organocatalyst containing 9-amino(9-deoxy)epi-cinchonidine and Brønsted acid and its application in asymmetric aldol reaction
作者:Ling Lan、Guangxin Xie、Tao Wu、Dandan Feng、Xuebing Ma
DOI:10.1039/c6ra08909g
日期:——
or p-substituted benzaldehydes bearing electron-withdrawing substituents (–X and –NO2) afforded good yields (71–96%) and excellent stereoselectivities (anti/syn = 94/6–98/2, 87–97% ee). It was found that the arm length (n) and acid capacity had significant effects on the cooperative catalysis of CDNH2 and Brøsted acid in the aldol reaction. After the completion of the aldol reaction, the catalysts could
Solid Acids as Heterogeneous Support for Primary Amino Acid-Derived Diamines in Direct Asymmetric Aldol Reactions
作者:Anneleen L. W. Demuynck、Li Peng、Filip de Clippel、Jozef Vanderleyden、Pierre A. Jacobs、Bert F. Sels
DOI:10.1002/adsc.201000871
日期:2011.3.28
non‐covalent immobilization of chiral primary amino acid‐derived diamines on organic and inorganic sulfonated solid acids through acid‐base interaction. With the commercial sulfonated fluoropolymer nafion® NR50 as support an optimal balance was found between activity and stereoselectivity of the supported catalyst in direct asymmetric aldol reactions of linear ketones and aromatic aldehydes. Under optimized
Chiral 1,2-diaminocyclohexane as organocatalyst for enantioselective aldol reaction
作者:Yi Liu、Junfeng Wang、Qi Sun、Runtao Li
DOI:10.1016/j.tetlet.2011.04.116
日期:2011.7
catalyze the asymmetric aldolreaction in MeOH–H2O. Cyclic ketones as aldol substrates gave the anti-β-hydroxyketone products with moderate to good yields, diastereoselectivity and enantioselectivity (up to 78% yield, >20:1 anti/syn, 94% ee). Hydroxyacetone as aldol substrate afforded the syn-α, β-dihydroxyketones as major products in up to 85% yield with good enantioselectivity (up to >20:1 syn/anti
一个简单的和可商购的手性1,2-二氨基环己烷作为催化剂,己二酸作为助催化剂能有效地催化在MeOH-H不对称醛醇缩合反应2 O.环酮类如醇醛底物,得到反-β-羟基酮产品具有中度至良好的收率,非对映选择性和对映选择性(高达78%的收率,抗/顺式> 20:1,94%ee)。羟丙酮作为醇醛底物以主要产物顺-α,β-二羟基酮的形式提供了高达85%的收率和良好的对映选择性(高达> 20:1 syn / anti,93%ee)。
Simple and practical direct asymmetric aldol reaction of hydroxyacetone catalyzed by 9-amino Cinchona alkaloid tartrates
procedure for the directaldolreaction of unprotected acetol and activated aromatic aldehydes catalyzed by 9-amino-9-epi-Cinchona ditartrates is presented. The protocol presented avoids the use of problematic solvents and toxic reagents as well as chromatographic purification of the products – instead a simple extraction has been applied for the isolation of purealdols from the reaction mixture. This