Synthesis and antisecretory and antiulcer activities of derivatives and analogs of 2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide
摘要:
New thioamide derivatives of 2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (29) and related compounds (in which the tetrahydrothiophene ring was replaced by tetrahydrothiopyran, tetrahydrofuran, 1,3-dithiane, or 1,3-oxathiane and where the pyridine ring was replaced by other nitrogen heterocycles) were synthesized and tested for their antisecretory and antiulcer activities. These thioamides were prepared according to one of the following methods: reaction of an isothiocyanate with the carbanion of the corresponding cyclic precursor (for secondary thioamides); reaction of ammonia or an amine with the dithio ester prepared from the same precursor (for primary, secondary, and tertiary thioamides). These thioamides were evaluated by the Shay method to measure their antisecretory activity and by the stress-induced-ulcer method to test their antiulcer activity. Structure-activity relationships are discussed. N-Methyl-2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (R.P. 40749, 30) exhibited activities that were at least 10 times higher than those reported for cimetidine.
An efficient protocol for the Cα-H heteroarylation of ethers, amides, and alcohols using air and light under mild conditions is described. The reaction is applicable to a wide spectrum of functional groups. The generation of C-radicals via photoinduced aerobic oxidation of ethers, amides, and alcohols is the key feature of the process. Control experiments suggest a radical pathway for the reaction
描述了在温和条件下使用空气和光对醚、酰胺和醇进行 Cα - H 杂芳基化的有效方案。该反应适用于广泛的官能团。通过醚、酰胺和醇的光诱导有氧氧化产生 C-自由基是该过程的关键特征。对照实验表明该反应的自由基途径。
Benzoyl Peroxide Promoted Radical<i>ortho</i>-Alkylation of Nitrogen Heteroaromatics with Simple Alkanes and Alcohols
作者:Lei Fang、Liangshun Chen、Jianjun Yu、Limin Wang
DOI:10.1002/ejoc.201403479
日期:2015.3
A catalytic amount of benzoylperoxide (BPO)-initiated cross-dehydrogenative coupling reaction of N-iminopyridine ylides with simplealkanes and alcohols leads to the corresponding 2-alkylpyridines with high regioselectivity in moderate to good yields without an additional reduction step to remove the activated group.
<i>sp</i><sup>3</sup> C–H Arylation and Alkylation Enabled by the Synergy of Triplet Excited Ketones and Nickel Catalysts
作者:Yangyang Shen、Yiting Gu、Ruben Martin
DOI:10.1021/jacs.8b07405
日期:2018.9.26
polypyridyl complexes. Additionally, such a platform provides a new strategy for streamlining the synthesis of complex molecules with high levels of predictable site-selectivity and preparative utility. Mechanistic experiments suggest that sp3 C-H abstraction occurs via HAT from the ketone triplet excited state. We believe this study will contribute to a more systematic utilization of triplet excited ketones
Mechanism of the Gif-Barton type alkane functionalization by halide and pseudohalide ions
作者:Francesco Minisci、Francesca Fontana
DOI:10.1016/s0040-4039(00)76237-x
日期:1994.2
The functionalization of alkanes by halide ions under the conditions of a Gif system can be explained by free-radical redox processes. The evidence is provided by trapping the intermediate alkyl radical by protonated heteroaromatic bases.
Visible light-induced Minisci reaction through photoexcitation of surface Ti-peroxo species
作者:Shimpei Naniwa、Akira Yamamoto、Hisao Yoshida
DOI:10.1039/d1cy00248a
日期:——
peroxo complex formed upon contact of hydrogen peroxide with the TiO2 surface can be selectively photoexcited by visible light to inject the photoexcited electron to the conduction band of TiO2. The electron can reduce H2O2 to a reactive oxygen species (ROS) and promote selectively the Minisci-type cross-coupling reactionbetween pyridinium ions and THF. A reaction test with a hole scavenger (methanol)
在酸性条件下,使用过氧化氢(H 2 O 2)和TiO 2光催化剂对吡啶进行四氢呋喃(THF)的光催化Minisci型官能化。在紫外光(λ = 360 nm)下,基于吡啶的反应选择性(S py)> 99%,而基于THF的反应选择性(S THF)低,如19%。相比之下,在可见光(λ = 400或420 nm)下,S py同样较高(> 99%),而S THF则是在紫外光下的两倍。过氧化氢与TiO 2接触后形成的表面过氧配合物表面可以被可见光选择性地光激发,将光激发电子注入TiO 2的导带中。电子可以将H 2 O 2还原为活性氧(ROS),并选择性地促进吡啶鎓离子与THF之间的Minisci型交叉偶联反应。用空穴清除剂(甲醇)进行的反应测试表明,H 2 O 2在紫外光下的空穴氧化导致较低的选择性,换句话说,在可见光下较高的选择性将归因于对H 2 O 2空穴氧化的抑制。 H 2 O 2。这些结果证明了通过使用H