Synthesis of Benzophenone Nucleosides and Their Photocatalytic Evaluation for [2+2] Cycloaddition in Aqueous Media
作者:Nadine Gaß、Hans-Achim Wagenknecht
DOI:10.1002/ejoc.201500885
日期:2015.10
solubility of the synthetic nucleosides in aqueous solution allowed for a photocatalytic intramolecular [2+2] cycloaddition of a quinolone substrate to take place in H2O/MeCN by irradiating the mixture with 365 nm light-emitting diode (LED) lamps. The MeO- and Me-substituted benzophenonenucleosides were subjected to these reaction conditions in substoichiometric amounts. After prolonged irradiation times
合成了四种与羰基相关的对位取代的二苯甲酮核苷(–NH2、–NMe2、–OMe 和 –Me),并通过它们的光学性质进行表征。取代基的给电子特性影响了这些核苷的光学性质,尤其是其紫外/可见吸收光谱中电荷转移带的红移。合成核苷在水溶液中的溶解度允许通过用 365 nm 发光二极管 (LED) 灯照射混合物,在 H2O/MeCN 中发生喹诺酮底物的光催化分子内 [2+2] 环加成。MeO-和Me-取代的二苯甲酮核苷以亚化学计量的量经受这些反应条件。经过长时间的照射,底物转化与产物分解竞争。基于我们的研究结果,我们确定 Me 取代的二苯甲酮核苷在开发具有光催化活性的 DNA 酶方面具有潜在的应用价值,可用于化学生物学的体内应用和水溶液中的对映选择性光催化。
An Ethynyl-Substituted 1,5,7-Trimethyl-3-azabicyclo[3.3.1]nonan-2-one as a Versatile Precursor for Chiral Templates and Chiral Photocatalysts
作者:Thorsten Bach、Felix Voss
DOI:10.1055/s-0029-1219920
日期:2010.6
The title compound was synthesized and separated into its enantiomers. The enantiomerically pure alkyne was ligated to several aryl azides and aryl halides. The resulting 7-substituted 1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-ones were used either as chiral templates in the intramolecular [2+2] photocycloaddition of 4-allyloxyquinolone (up to 72% ee) or as a chiral photocatalyst for the intramolecular [2+2] photocycloaddition of 4-(3-butenyloxy)quinolone (up to 79% ee with 10 mol% catalyst).
Synthesis of cyclobuta[c]quinolin-3-ones. Intra- and inter-molecular photocycloadditions of 4-alkoxy-2-quinolone systems with olefins
作者:Chikara Kaneko、Toshihiko Naito、Masanori Somei
DOI:10.1039/c39790000804
日期:——
sole product, whereas 4-(but-3-enyloxy)-2-quinolone (7) led to a mixture (ca. 7 : 1) of adducts (8) and (9); base treatment of the adducts (2), (8), and (9) gave rise to the novel 1,2-dihydrocyclobuta[c]quinolin-3(4H)ones (3), (10), and (11) in quantitative yields.
辐照4-烯丙氧基-2-喹诺酮(1)得到四环加合物(2)作为唯一产物,而4-(丁-3-烯氧基)-2-喹诺酮(7)产生混合物(约7: 1)加合物(8)和(9);加合物(2),(8)和(9)的碱处理产生了新的1,2-二氢环丁[ c ]喹啉-3(4 H)酮(3),(10)和(11)以定量的产量。
A designed photoenzyme for enantioselective [2+2] cycloadditions
作者:Jonathan S. Trimble、Rebecca Crawshaw、Florence J. Hardy、Colin W. Levy、Murray J. B. Brown、Douglas E. Fuerst、Derren J. Heyes、Richard Obexer、Anthony P. Green
DOI:10.1038/s41586-022-05335-3
日期:2022.11.24
accessible to biocatalysis.5-12 Installation of a genetically encoded photosensitiser into the beta-propeller scaffold of DA_20_0013 converts a de novo Diels-Alderase into a photoenzyme for [2+2]-cycloadditions (EnT1.0). Subsequent development and implementation of a platform for photoenzyme evolution afforded an efficient and enantioselective enzyme (EnT1.3, up to 99% e.e.) that can promote intramolecular
将新的催化模式编程到蛋白质中的能力将允许开发具有超出自然界中发现的功能的酶家族。为此,遗传密码扩展方法具有特别的前景,因为它允许将新的功能元件作为非规范氨基酸侧链选择性地引入蛋白质中。 1-4在这里,我们利用扩展的遗传密码来开发一种通过三重态能量转移催化发挥作用的光酶,这是有机合成中的一种多功能反应模式,目前生物催化无法实现。 5-12将基因编码的光敏剂安装到 DA_20_00 13的 β 螺旋桨支架中,将de novo Diels-Alderase 转化为用于 [2+2]-环加成的光酶 (EnT1.0)。随后光酶进化平台的开发和实施提供了一种高效的对映选择性酶(EnT1.3,高达 99% ee ),可以促进分子内和双分子环加成,包括已证明用小分子催化剂选择性实现具有挑战性的转化。 EnT1.3 的转换次数超过 300 次,与小分子光催化剂相比,它可以在有氧条件和环境温度下有效运行。 EnT1