Fe 3 O 4 @SiO 2 [电子邮件保护] II是通过二氧化硅包覆的磁性纳米颗粒,脲三唑和CoCl 2制备的。这种有机-无机杂化复合物,使用新戊酸酐,K 2 S 2 O 8和PPh 3作为导向基团,对游离酚和萘的区域选择性邻亚磺酰化表现出良好至优异的催化活性。分别用作氧化剂和添加剂。通过使用不同的技术(例如FT-IR,TGA,DTG,TEM,SEM,EDS,ICP和VSM分析)对新合成的催化剂进行了全面表征。与用于C H键活化和官能化的昂贵过渡金属相比,钴具有竞争力的价格,可及性和较低的毒性构成了该方法的宝贵优势。而且,这种多相催化剂可以在五个循环后被磁回收和再利用而不会显着损失其催化活性。
Nitrosonium ion catalysis: aerobic, metal-free cross-dehydrogenative carbon–heteroatom bond formation
作者:Luis Bering、Laura D’Ottavio、Giedre Sirvinskaite、Andrey P. Antonchick
DOI:10.1039/c8cc08328b
日期:——
coupling of heteroarenes with thiophenols and phenothiazines has been developed under mild and environmentally benign reaction conditions. For the first time, NOx+ was applied for catalytic C–S and C–N bond formation. A comprehensive scope for the C–H/S–H and C–H/N–H cross-dehydrogenative coupling was demonstrated with >60 examples. The sustainable cross-coupling conditions utilize ambient oxygen as the
杂芳烃与硫酚和吩噻嗪的催化交叉脱氢偶联已在温和且环境友好的反应条件下得到发展。首次将NO x +用于催化C–S和C–N键的形成。用60多个例子证明了C–H / S–H和C–H / N–H交叉脱氢偶联的综合范围。可持续的交叉偶联条件利用环境氧作为末端氧化剂,而水是唯一的副产物。
Transition-Metal-Free Synthesis of Unsymmetrical Diaryl Chalcogenides from Arenes and Diaryl Dichalcogenides
A transition-metal-free synthetic method has been developed for the synthesis of unsymmetrical diaryl chalcogenides (S, Se, and Te) from diaryl dichalcogenides and arenes under oxidative conditions by using potassium persulfate at room temperature. Variously substituted arenes such as anisole, thioanisole, diphenyl ether, phenol, naphthol, di- and trimethoxy benzenes, xylene, mesitylene, N,N-dimethylaniline
已开发出一种无过渡金属的合成方法,该方法用于在室温条件下通过使用过硫酸钾,在氧化条件下由二芳基二卤化锑和芳烃合成不对称的二芳基硫属元素化物(S,Se和Te)。各种取代的芳烃,例如苯甲醚,硫代苯甲醚,二苯醚,苯酚,萘酚,二和三甲氧基苯,二甲苯,均三甲苯,N,N-二甲基苯胺,溴取代的芳烃,萘和二芳基二卤化碳经历了碳硫族键形成反应在三氟乙酸中生成不对称的二芳基硫属元素化物。为了理解反应的机理部分,由77进行了详细的中间体原位表征通过使用二苯基二硒化物为底物进行Se NMR光谱分析。77 Se NMR研究表明,亲电子物质ArE +是由二芳基二卤化二硫化物与过硫酸盐在三氟乙酸中反应生成的。芳基硫属元素离子对芳烃的亲电攻击可能是芳基-硫属元素键形成的原因。
Co(II)-catalyzed regioselective clean and smooth synthesis of 2-(aryl/alkyl-thio)phenols via sp2 C H bond activation
作者:Abed Rostami、Vahid Khakyzadeh、Mohammad Ali Zolfigol、Amin Rostami
DOI:10.1016/j.mcat.2018.04.020
日期:2018.6
The first example of a smooth, practical and useful strategy for the preparation of ortho-aryl/alkyl sulfenyl phenols by using the reaction of aryl/alkyl thiols with phenols in the presence cobalt as catalyst, and with the assistance of acetic anhydride as directing group via CH bond activation, was developed. Described method enables to form selectively CS bond without any ligand, oxidant, and aryl/alkyl
Iron or boron-catalyzed C–H arylthiation of substituted phenols at room temperature
作者:Hua Tian、Changjin Zhu、Haijun Yang、Hua Fu
DOI:10.1039/c4cc03600j
日期:——
A simple, efficient and environmentally friendly method for iron or boron-catalyzed C–H arylthiation of substituted phenols at room temperature has been developed, and the corresponding diaryl sulfides were prepared in good to excellent yields.
Direct sulfenylation and selenylation of phenols using a stoichiometric amount of FeCl3 under an oxygen atmosphere has been developed. The chalcogenated phenols were shown to be suitable for preparing S- and Se-containing compounds using the reaction of the remaining hydroxy group.