描述了新型氢过氧阿马酸1b-d的合成及其作为非水介质中广泛的氮,硫和磷杂原子的可再生化学选择性亲电子氧化剂的潜力。1b,c与仲胺10f,g的反应产生羟基磺酰胺2b,c和硝酮11f或自由基11g,这取决于底物和化学计量,而叔胺10a-d给出氧化胺11a-d。化合物1c,d将各种硫醚12a-g平滑地氧化为亚砜13a-g,其通过色谱法以接近定量的产率分离。通过用酸化的H 2 O 2处理2c,从1c再生出1c。1c与1,4-噻吨12f反应的动力学研究表明,该反应遵循二级动力学,底物上的第一级和氧化剂中的第一级,其第二级速率常数比与过氧化氢和叔丁基氢过氧化物的相应反应的速率大几个数量级,而无需任何酸或重金属催化剂。膦14a,b也被1c容易地以定量收率氧化成各自的膦氧化物15a,b。反应可以在环境温度或更低的温度下进行,并且似乎是通过非自由基机理进行的。反应对空间和电子因素均敏感。b容易获得定量产量。
Synthesis and elastase-inhibiting activity of 2-pyridinyl-isothiazol-3(2H)-one 1,1-dioxides
作者:Alexander Eilfeld、Camino M. González Tanarro、Maxim Frizler、Joachim Sieler、Bärbel Schulze、Michael Gütschow
DOI:10.1016/j.bmc.2008.07.049
日期:2008.9
The synthesis of a series of new isothiazol-3(2H)-one1,1-dioxides with halogenated (mostly fluorinated) pyridinyl and pentafluorophenyl substituents at 2-position is reported. These compounds (18-24) became easily accessible from 2-thiocyanato-1-carboxaldehydes and aminopyridines, pentafluoroaniline, respectively, by an isothiazolium cyclization-oxidation route. Compound 21 exhibited an IC(50) value
Synthesis of N,N’-Linked Isothiazolium Salts via Intramolecular Cyclocondensation of Hydrazonium Salts
作者:Valerija M. Zakharova、Anja Siegemund-Eilfelda、Joachim Sieler、Bärbel Schulze
DOI:10.1515/znb-2006-0413
日期:2006.4.1
-thiocyanatovinyl aldehydes with N-amino heterocycles leads to formation of α, β - unsaturated hydrazonium salts dependent on the functional surroundings. The latter can undergo further intramolecular cyclocondensation giving rise to N,N′-linked isothiazolium salts as the final product. The isolated hydrazonium salts, not undergoing ring formation, have s-trans conformation of the azadiene system
Synthesis of 2-Phenylisothiazol-3(2H)-One 1,1-Dioxides: Inhibitors of Human Leukocyte Elastase
作者:Michael Gütschow、Markus Pietsch、Kathleen Taubert、Tonia H. E. Freysoldt、Bärbel Schulze
DOI:10.1515/znb-2003-0115
日期:2003.1.1
Abstract A series of 2-phenylisothiazol-3(2H)-one1,1-dioxides 14a - q were synthesized by oxidation of isothiazolium perchlorates 12. The inhibition of the serine proteases cathepsin G, chymotrypsin and human leukocyte elastase (HLE) by 14 was investigated. Some 4,5-diphenyl substituted derivatives ( 14i - k) were found to inhibit HLE in a time-dependent manner and exhibited kobs/[I] values > 500
Synthesis of 2-Nitrothiophenes <i>via</i>
Tandem Henry Reaction and Nucleophilic Substitution on Sulfur from β-Thiocyanatopropenals
作者:Lin Rong、Yingxia Shen、Guoxi Xiong、Yuefa Gong
DOI:10.1002/jhet.3446
日期:2019.2
A new synthetic route of 2‐nitrothiophenes was described through a tetra‐n‐butylammonium fluoride‐promoted or diisopropylethylamine‐promoted tandem Henry reaction and nucleophilicsubstitution of nitromethane with 3‐thiocyanatopropenals, which were conveniently prepared by the replacement reaction of 3‐chloropropenals with potassium thiocyanate under a mild acidic condition.
3-hydroperoxy-, 3-hydroxy- and 3-oxoisothiazole 1,1-dioxides have been synthesized by the sequence of oxidation reactions from N,N′-linked isothiazolium perchlorates with hydrogenperoxide, MMPP, and pyridinium dichromate. Isothiazolium salts without acceptor substituents did not give N-substituted sultams. Novel N,N′-bisazaheterocycles were investigated as inhibitors of acetylcholinesterase (AChE) and human leukocyte