Formation of the Dimethylbenzimidazole Ligand of Coenzyme B12 under Physiological Conditions by a Facile Oxidative Cascade
摘要:
Dimethylbezimidazole, the axial ligand of vitamin B-12, is synthesized from riboflavin by a two-electron oxidation, a retro-aldol condensation, and a second two-electron oxidation. This oxidative cascade readily takes place nonenzymatically under physiological conditions.
Synthesis of 2-Alkoxy/Thioalkoxy Benzo[<i>d</i>]imidazoles and 2-Thione Benzo[<i>d</i>]imidazoles via a Phase-Based, Chemoselective Reaction
作者:Hyo-Jeong Yoon、Seung-Ju Yang、Young-Dae Gong
DOI:10.1021/acscombsci.7b00106
日期:2017.12.11
2-Alkoxy/thioalkoxy benzo-[d]-imidazole and 2-thione benzo-[d]-imidazole libraries were constructed in solutionphase and on solidphase, respectively. The key step in this work is the phase-based chemoselective reaction of the 2-mercaptobenzo-[d]-imidazole intermediate with benzyl chloride (solutionphase) and Merrifield resin (solidphase). In the solution-phase case, benzyl chloride reacted with the thiol
分别在溶液相和固相上构建了2-烷氧基/硫代烷氧基苯并-[ d ]-咪唑和2-硫酮苯并-[ d ]-咪唑的文库。这项工作的关键步骤是2-巯基苯并-[ d ]-咪唑中间体与苄基氯(溶液相)和Merrifield树脂(固相)的基于相的化学选择性反应。在溶液相情况下,苄基氯与2-巯基苯并-[ d ]-咪唑的巯基反应,而在固相情况下,将Merrifield树脂引入苯并-[ d ]-咪唑的内部胺基。提供所需的2-烷氧基/硫代烷氧基苯并-[ d]-咪唑类似物,我们在溶液相中使用了各种烷基卤,醇和硫醇,在固相中获得了2-硫酮苯并-[ d ]-咪唑衍生物,我们使用了各种烷基卤和硼酸。最后,为了测量具有口服活性的药物潜力和三维(3D)空间中的分子多样性,我们计算了理化性质并显示了能量最小的3D结构。结果,来自溶液相和固相的库在3D空间中的物理化学性质和骨骼多样性方面显示出不同的特征。
Concise route to a series of novel 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones
作者:Steven Gunawan、Gary Nichol、Christopher Hulme
DOI:10.1016/j.tetlet.2012.01.080
日期:2012.3
This Letter presents a novel three step solution phase protocol to synthesize 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones. The strategy utilizes ethyl glyoxalate and mono-N-Boc-protected-o-phenylenediamine derivatives in the Ugi-Azide multi-component reaction (MCR) to generate a unique 1,5-disubstituted tetrazole. Subsequent acid treatment stimulates a simultaneous Boc deprotection and intramolecular cyclization
Expeditious Routes to Polycyclic Molecular Frameworks via One-Pot, Two-Step Ugi Ring-Closing Sequences
作者:Christopher Hulme、Zhigang Xu、Fabio De Moliner、Alexandra Cappelli、Muhammed Ayaz
DOI:10.1055/s-0033-1340219
日期:——
Ugi condensation between ethyl glyoxylate, isonitriles, N -Boc-α-amino acids, and mono - N -Boc-protected diamines followed by a series of acid-promoted cyclization steps in a one-pot fashion is reported. This process allows for the assembly of complex polycyclic structures by means of just two simple synthetic operations and a single chromatographic purification in high overall yields. Of note, the
一个非常通用和强大的多组分反应方案,包括乙醛酸乙酯、异腈、N-Boc-α-氨基酸和单-N-Boc-保护的二胺之间的 Ugi 缩合,然后是一系列酸促进的环化步骤-锅时尚报道。该过程允许通过仅两个简单的合成操作和单次色谱纯化以高总产率组装复杂的多环结构。值得注意的是,据报道,第一个支架源自高度选择性的闭环事件序列,涉及三个内部氨基亲核试剂。
Synthesis of substituted 8-aminoquinolines and phenanthrolines through a Povarov approach
The synthesis of 8-aminoquinolines and 1,10-phenanthrolines with substituents in α of the nitrogen has been performed through an inverse-demanding aza-Diels–Alder (Povarov reaction) in the fluoroalcohols TFE or HFIP. This path involves simple starting materials: 1,2-phenylenediamines, enol ethers and aldehydes.
Conversion of a Dehalogenase into a Nitroreductase by Swapping its Flavin Cofactor with a 5-Deazaflavin Analogue
作者:Qi Su、Petrina A. Boucher、Steven E. Rokita
DOI:10.1002/anie.201703628
日期:2017.8.28
formation of the hydroxylamine intermediates. Efficient use of these enzymes also requires a regenerating system for NAD(P)H to avoid the costs associated with this natural reductant. Iodotyrosine deiodinase is a member of the same structural superfamily as many nitroreductases but does not directly consume reducing equivalents from NAD(P)H, nor demonstrate nitroreductase activity. However, exchange