在室温下,在化学计量或催化量的三乙胺存在下,丙二酸半硫酯(MAHT)和丙二酸半氧基酯(MAHO)与酮和醛亲电子发生脱羧亲核加成反应。在无金属条件下进行这些反应的能力使得能够对导致1的反应路径进行详细的机理分析。亲核后加成/脱羧前中间体的1 H NMR光谱表征和该中间体可逆形成后不可逆脱羧的实验证据。还确定了反应路径中每个键形成/键断裂步骤的速率常数,从而阐明了在这些过程中MAHO和MAHT亲核试剂之间不同的反应性。最后,通过这些研究获得的机理见解已被用于开发新的脱羧香豆素合成方法。
Regioselective Synthesis of 4,5-Dihydro-6<i>H</i>
-oxepino[3,2-<i>c</i>
]chromene-2,6(3<i>H</i>
)-diones through Palladium-Catalyzed Intramolecular Alkoxycarbonylation of 3-Allyl-4-hydroxycoumarins
作者:D. Oliver Sosa、Karla Almaraz、Manuel Amézquita-Valencia
DOI:10.1002/ejoc.201900649
日期:2019.8.7
This work presents a regioselective route to synthesize seven‐membered ring lactones fused to coumarin scaffold in good yields and high regioselectivity. Additionality, the carbonylation reaction does not require acidic conditions and proceeds in the absence of any other additive such as hydrogen (H2).
Enantioselective Construction of Amino Carboxylic‐Phosphonic Acid Derivatives Enabled by Chiral Amino Thiourea‐Catalyzed Decarboxylative Mannich Reaction
作者:Xue‐Qi Wang、Fang‐Fang Feng、Jing Nie、Fa‐Guang Zhang、Jun‐An Ma
DOI:10.1002/adsc.202200306
日期:2022.6.7
An asymmetric decarboxylativeMannichreaction of phosphonate sultam-ketimines with malonic acid half esters is developed enabled by saccharide-derived bifunctional amino thiourea catalysis. This protocol provides access to a broad range of α-amino-β-carboxylic phosphonates featuring the N,P-containing tetrasubstituted stereocenters with 78–99% ee. Further synthetic derivatizations could allow the
通过糖衍生的双功能氨基硫脲催化,开发了膦酸磺胺酮亚胺与丙二酸半酯的不对称脱羧曼尼希反应。该协议提供了广泛的 α-氨基-β-羧酸膦酸盐,具有 78–99% ee 的含N、P的四取代立体中心。进一步的合成衍生化可以允许将酰胺、醇和氮杂环丁烷支架引入核心结构。
Rational Design and Synthesis of Methyl-β-<scp>d</scp>-galactomalonyl Phenyl Esters as Potent Galectin-8<i>N</i> Antagonists
作者:Brijesh Patel、Chandan Kishor、Todd. A. Houston、Hadas Shatz-Azoulay、Yehiel Zick、Yaron Vinik、Helen Blanchard
DOI:10.1021/acs.jmedchem.0c00602
日期:2020.10.22
β-galactoside-recognizing protein having an important role in the regulation of bone remodeling and cancer progression and metastasis. Methyl β-d-galactopyranoside malonyl aromatic esters have been designed to target and engage with particular amino acid residues of the galectin-8N extended carbohydrate-binding site. The chemically synthesized compounds had in vitro binding affinity toward galectin-8N
Galectin-8是一种β-半乳糖苷识别蛋白,在调节骨骼重塑以及癌症进展和转移中具有重要作用。已经设计了甲基β- d-吡喃半乳糖苷丙二酰芳族酯以靶向并与galectin- 8N延伸的碳水化合物结合位点的特定氨基酸残基接合。化学合成的化合物对galectin-8 N具有体外结合亲和力通过等温滴定热量法评估,其范围为5–33μM。这种亲和力与化合物抑制SUM159乳腺癌细胞系中galectin-8诱导的趋化因子和促炎细胞因子表达的能力直接相关。X射线晶体结构测定表明,这些单糖基的化合物结合半乳凝素8 Ñ通过接合其独特的精氨酸(Arg59),同时交联到位于横跨糖结合位点的另一精氨酸(Arg45)。这种基于结构的药物设计方法导致了新型单糖半乳糖拮抗剂的发现,其最强结合的化合物(K d 5.72μM)比二糖乳糖紧紧7倍。
Decarboxylative Ketone Aldol Reactions: Development and Mechanistic Evaluation under Metal-Free Conditions
作者:Nicole Blaquiere、Daniel G. Shore、Sophie Rousseaux、Keith Fagnou
DOI:10.1021/jo901022j
日期:2009.8.21
acid half oxyesters (MAHOs) are shown to undergo decarboxylative nucleophilic addition reactions with ketone and aldehyde electrophiles in the presence of stoichiometric or catalytic quantities of triethylamine at room temperature. The ability to perform these reactions undermetal-freeconditions has enabled a detailed mechanistic analysis of the reaction pathway leading to the 1H NMR spectroscopic
在室温下,在化学计量或催化量的三乙胺存在下,丙二酸半硫酯(MAHT)和丙二酸半氧基酯(MAHO)与酮和醛亲电子发生脱羧亲核加成反应。在无金属条件下进行这些反应的能力使得能够对导致1的反应路径进行详细的机理分析。亲核后加成/脱羧前中间体的1 H NMR光谱表征和该中间体可逆形成后不可逆脱羧的实验证据。还确定了反应路径中每个键形成/键断裂步骤的速率常数,从而阐明了在这些过程中MAHO和MAHT亲核试剂之间不同的反应性。最后,通过这些研究获得的机理见解已被用于开发新的脱羧香豆素合成方法。