Biocatalytic Synthesis of α,β-Unsaturated 2-Keto Acids and Derivatives Using the Promiscuous Aldolase, NahE
作者:David R. J. Palmer、Douglas J. Fansher、Niza Ngwira、Ahmad Reza Salehi、Jerome Woods、Amanda Cascão
DOI:10.1055/a-1953-1509
日期:2023.1
Type I aldolases catalyze carbon–carbon bond-forming reactions to form a diverse set of products in nature but often display high selectivity for their natural substrates. One such aldolase, NahE, is known to catalyze the condensation of pyruvate with a wide range of aldehydes to give trans-4-phenyl-2-oxo-3-butenoic acids under mild aqueous conditions. These α,β-unsaturated 2-oxo acids are versatile
I 型醛缩酶催化碳-碳键形成反应,在自然界中形成多种产物,但通常对其天然底物表现出高选择性。已知其中一种醛缩酶 NahE 可催化丙酮酸与多种醛的缩合反应生成反式-4-苯基-2-氧代-3-丁烯酸在温和的水性条件下。这些 α,β-不饱和 2-氧代酸是用于合成转化的通用中间体。NahE 还用于合成 α-氟代-β-羟基酯、β-羟基酯和喹醛酸。然而,尚未对天然 NahE 催化的醛醇缩合反应进行实际规模的底物范围的彻底研究。在这里,我们报告 NahE 可以接受 >35(杂)芳香族和脂肪族醛。大多数来自取代苯甲醛的缩合产物的分离产率 > 95%,无需进一步纯化,而非苯甲醛底物的相应产物的分离产率在 26% 和 98% 之间。反应可以以克级进行。这些产品可以转换成α,β-不饱和羧酸在两个步骤中的产率高达 93%。该反应序列也使用全细胞进行,产率高达 79%。这项工作表明,NahE 是一种稳健、高效且用途广泛的有机合成催化剂。
Enantioselective Si‐H Insertion of Arylvinyldiazoesters Promoted by Rhodium(I)/Diene Complexes
An enantioselective Si‐H insertion between α‐arylvinyldiazoesters and silanes has been developed by employing rhodium(I)/chiral diene complex as the catalyst. This protocol offers a catalytic asymmetric approach to various chiral silanes containing α‐arylvinyl functionality at room temperature with good enantiocontrol (89‐99% ee). Transformation of the resulting enantiomerically enriched α‐arylvinyl‐α‐silyl
Deracemisation of aryl substituted α-hydroxy esters using Candida parapsilosis ATCC 7330: effect of substrate structure and mechanism
作者:B. Baskar、N.G. Pandian、K. Priya、Anju Chadha
DOI:10.1016/j.tet.2005.09.104
日期:2005.12
Candida parapsilosis ATCC 7330 was found to be an efficient biocatalyst for the deracemisation of aryl alpha-hydroxy esters (65-85% yield and 90-99% ee). A variety of aryl and aryl substituted alpha-hydroxy esters were synthesized to reflect steric and electronic effects on biocatalytic deracemisation. The mechanism of this biocatalytic deracemisation was found to be stereoinversion. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis and photophysical evaluations of fluorescent quaternary bipyridyl-1,8-naphthalimide conjugates as nucleic acid targeting agents
作者:Gary J. Ryan、Robert B.P. Elmes、Susan J. Quinn、Thorfinnur Gunnlaugsson
DOI:10.1080/10610278.2011.638381
日期:2012.3
A family of organic molecules containing the DNA intercalating chromophores, 4-nitro- and 4-amino 1,8-naphthalimide, conjugated to a diquat derivative by an 'orthogonal' phenyl spacer have been prepared and characterised. Their binding interactions with double-stranded DNA were studied by a variety of spectroscopic techniques. These charged organic compounds are found to exhibit excellent binding affinities to DNA with binding constants comparable to those exhibited by metal complexes.
Menon-Rudolph, Sunitha; Nishikawa, Sadakatsu; Zeng, Xiaoping, Journal of the American Chemical Society, 1992, vol. 114, # 26, p. 10110 - 10112
作者:Menon-Rudolph, Sunitha、Nishikawa, Sadakatsu、Zeng, Xiaoping、Jordan, Frank