<i>N</i>-Primary-Amine-Terminal β-Turn Tetrapeptides as Organocatalysts for Highly Enantioselective Aldol Reaction
作者:Feng-Chun Wu、Chao-Shan Da、Zhi-Xue Du、Qi-Peng Guo、Wei-Ping Li、Lei Yi、Ya-Ning Jia、Xiao Ma
DOI:10.1021/jo9005766
日期:2009.7.3
solution. They were first applied to catalyze aldolreactions, and were found to be effective catalysts for the transformations. The tetrapeptide Val-d-Pro-Gly-Leu-OH (1g) was the optimal organocatalyst. It was shown that the intensive β-turn conformation, indicated by CD and NOESY spectra, contributed to the (R)-aldol and high enantioselectivity of the reaction of acetone in MeOH, whereas the sharply varied
设计并合成了四肽,该四肽包含一个终止的伯胺和构象受限的d -Pro-Gly或d -Pro-Aib(2-氨基异丁酸)链段作为强β-转核元素,并通过N-模块二肽与溶液中的C模块二肽。它们首先被用于催化羟醛反应,并被发现是有效的转化催化剂。四肽Val- d -Pro-Gly-Leu-OH(1g)是最佳的有机催化剂。结果表明,在密集的β转角构象,通过CD和NOESY光谱表明,促成了(ř)-丙酮中的丙酮反应具有较高的对映选择性,而急剧变化的构象应有助于1,2-二氯乙烷(DCE)中反应的低对映选择性和(S)产物。羟基丙酮反应中的不对称诱导不受溶剂的影响,在MeCN中添加1克添加剂(S)-BINOL可达到主要的反产物。
Direct Asymmetric Aldol Reaction Catalyzed by C2-Symmetrical Chiral Primary Amine Organocatalysts
作者:Gong-Jian Zhu、Chao-Shan Da、Ya-Ning Jia、Xiao Ma、Lei Yi
DOI:10.2174/157017810790533904
日期:2010.1.1
C-2-symmetrical chiral primaryamines were synthesized from chiral BINOL and diamines. Then their catalytic activities in the asymmetricaldolreactions were evaluated, and the result indicated that 1c was the optimal organocatalyst. The reaction of a variety of aromatic aldehydes with aliphatic ketones, catalyzed by 20 mol % 1c in the addition of benzoic acid in carbon tetrachloride, afforded the aldol products
A Novel Proline-Valinol Thioamide Small Organic Molecule for a Highly Enantioselective Direct Aldol Reaction
作者:Bing Wang、Guo-hong Chen、Ling-yan Liu、Wei-xing Chang、Jing Li
DOI:10.1002/adsc.200900427
日期:2009.10
amino alcohol L-valinol, has been found to be an active catalyst for the direct aldol reaction of various aldehydes with acetone, cyclohexanone or cyclopentanone at 0 °C. Using only 2 mol% loading of this organocatalyst, the reaction could give high enantioselectivity with up to 96% enantiomeric excess for the reaction of 2-nitrobenzaldehyde with acetone. And as for the cyclohexanone, the excellent diastereoselectivity
Highly Enantioselective Direct Asymmetric Aldol Reaction Catalyzed by 4,5-Methano-<i>L</i>-proline
作者:Yukun Zhang、Jun Zhu、Na Yu、Han Yu
DOI:10.1002/cjoc.201400732
日期:2015.2
The 4,5‐methano‐L‐proline was used as chiral organocatalysts in direct asymmetric aldolreactions. Under the optimal conditions, excellent enantioselectivities (up to 99% ee) were obtained with high chemical yields (up to 95%) for a series of aldehydes using only 5 mol% catalyst loading. To show the practicality of the method, the reaction was tested at a large scale. The reaction was complete in 16