Nuclear Magnetic Resonance Studies of Sulfur Compounds. II. The Substituent Effect on Geminal Coupling Constants and on Magnetic Nonequivalence of the Methylene Protons of Sulfoxides.
作者:Motohiro Nishio
DOI:10.1248/cpb.15.1669
日期:——
Nuclear magnetic resonance spectra were obtained for a number of sulfoxides, whose methylene protons are magnetically nonequivalent. The coupling constants between these protons depend on the electronic properties of the substituent adjacent to the coupling protons. The substituent effect on magnetic nonequivalence was also studied and it is demonstrated that the electronic properties of the substituent constitute an important factor responsible for the magnitude of magnetic nonequivalence.
Synthesis of <i>N</i>-alkylated 2-pyridones through Pummerer type reactions of activated sulfoxides and 2-fluoropyridine derivatives
作者:Gang Hu、Jiaxi Xu、Pingfan Li
DOI:10.1039/c8ob00860d
日期:——
excellent yields through a one-pot procedure involving either normal or interrupted Pummerer reactions between triflic anhydride activated sulfoxides and 2-fluoropyridine derivatives, followed by hydrolysis. This is a rare case that uses 2-fluoropyridine as a nucleophile in Pummerer type reactions.
Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in shortsteps from inexpensive commercially available starting materials. The single-crystal
Synthesis, spectral characterization, crystal structure and catalytic activity of a novel dioxomolybdenum Schiff base complex containing 4-aminobenzhydrazone ligand: A combined experimental and theoretical study
A novel dioxomolybdenum Schiff base complex, [MoO2(L)(H2O)], was synthesized by the reaction of MoO2(acac)2 and an ONO donor Schiff base ligand (H2L: (E)-4-amino-N'-(3-ethoxy-2-hydroxybenzylidene)benzohydrazide) derived by the condensation of 4-aminobenzohydrazide and 3-ethoxysalicylaldehyde. The synthesized ligand and complex were characterized by various spectroscopic techniques like FT-IR, 1H NMR
一种新颖的二氧合钼席夫碱配合物,[的MoO 2(L)(H 2 O)],通过的MoO的反应合成2(ACAC)2和供体ONO席夫碱配体(ħ 2 L: (E) -4-氨基-N' -(3-乙氧基-2-羟基苯甲酰肼)由4-氨基苯甲酰肼和3-乙氧基水杨醛缩合而成。合成的配体和配合物通过各种光谱技术如 FT-IR、1 H NMR、13C NMR和元素分析(CHN)。通过单晶X射线衍射分析(SC-XRD)证实了配合物的结构。从衍射研究中收集的数据表明,复合物中中心金属离子周围的几何形状是扭曲的八面体。合成化合物的理论计算,通过 DFT 使用 B3LYP 和 PBE0 理论水平在 Def2-TZVP 基组上进行,表明计算结果与实验结果一致。此外,通过在乙醇中的 30% H 2 O 2水溶液存在下氧化芳基和烷基硫化物来研究配合物的催化效率。
Synthesis of <i>N</i>-Alkylpyridin-4-ones and Thiazolo[3,2-<i>a</i>]pyridin-5-ones through Pummerer-Type Reactions
作者:Jingjia Huang、Gang Hu、Shaoyu An、Dongding Chen、Minglei Li、Pingfan Li
DOI:10.1021/acs.joc.9b01672
日期:2019.8.2
involving either normal or interrupted Pummerer reactions between triflic anhydride-activated sulfoxides and 4-fluoropyridine derivatives, followed by hydrolysis. On the other hand, triflic anhydride-activated benzyl 6-fluoro-2-pyridyl sulfoxide could react with alkenes or alkynes to afford thiazolo[3,2-a]pyridin-5-ones, via the pyridinium salt intermediates.
N-烷基化的4-吡啶酮是通过一锅法获得的,该方法涉及三氟甲酸酐活化的亚砜和4-氟吡啶衍生物之间的正常或间断的Pummerer反应,然后进行水解。另一方面,三氟甲磺酸酐活化的苄基6-氟-2-吡啶基亚砜可以通过吡啶鎓盐中间体与烯烃或炔烃反应生成噻唑并[3,2 - a ]吡啶-5-酮。