Highly efficient AgNO<sub>3</sub>
-catalyzed approach to 2-(benzo[<i>d</i>
]azol-2-yl)phenols from salicylaldehydes with 2-aminothiophenol, 2-aminophenol and benzene-1,2-diamine
derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2‐aminothiophenol, 2‐aminophenol or benzene‐1,2‐diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO3 as a readily available and low‐cost benign oxidant at low catalyst loadings with
描述了一种新的,便捷有效的AgNO 3催化策略,用于制备2-(苯并[ d ] azol-2-基)苯酚衍生物,产率高至优异(63-98%)。反应在温和的反应条件下通过取代的水杨醛与2-氨基硫酚,2-氨基酚或苯1,2-二胺之间的缩合/分子内亲核加成/氧化过程进行。值得注意的是,该反应利用廉价的AgNO 3作为易于获得的低成本良性氧化剂,催化剂负载低,具有出色的官能团耐受性。
Titanium Complexes of Salicylbenzoxazole and Salicylbenzothiazole Ligands for the Ring-Opening Polymerization of ε-Caprolactone and Substituted ε-Caprolactones and Their Copolymerizations
Two series of titaniumcomplexes, including salicylbenzoxazole titaniumcomplexes (1–4) and salicylbenzothiazole titaniumcomplexes (5–8), were successfully synthesized and characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction crystallography (for 2 and 5). The 1H NMR spectra of complexes 7 and 8 reveal fluxional behavior in solution at room temperature, and the activation parameters
成功合成了水杨基苯并恶唑钛配合物(1-4)和水杨基苯并噻唑钛配合物(5-8)两大系列钛配合物,并通过核磁共振光谱、元素分析和X射线衍射晶体学(2和5 )对其进行了表征。配合物7和8的1 H NMR 光谱揭示了室温下溶液中的流动行为,活化参数由甲苯-d 8中的变温 (VT) NMR 光谱的线形分析确定:对于7,Δ H ⧧= 73.0 ± 1.8 kJ mol –1,ΔS ⧧ = 22.1 ± 5.5 J mol –1 K –1;对于8,Δ H ⧧ = 73.7 ± 1.2 kJ mol –1,Δ S ⧧ = 20.3 ± 3.8 J mol –1 K –1。ΔS⧧的正值表明异构化是通过解离机制发生的。所有配合物都是 ε-己内酯 (ε-CL) 和三种取代的 ε-CL 开环聚合的活性引发剂:γ-甲基-ε-己内酯 (γMeCL)、γ-乙基-ε-己内酯 (γEtCL) 和γ-苯基-ε-己内酯(γPh
ENZYMATIC ANALYSIS USING SUBSTRATES THAT YIELD FLUORESCENT PRECIPITATES