A new efficient synthesis of indolo[3,2,1-jk]carbazoles by the palladium-catalyzed cyclization of N-(2-bromoaryl)carbazoles is described. The reaction involves intramolecular C–C bond formation, coupled with the cleavage of a C–X bond and a C–H bond on carbazole ring. Substitutions on N-aryl core with either electron-donating or electron-withdrawing groups are introduced, and different reaction factors
描述了一种新的高效合成吲哚[3,2,1- jk ]咔唑的方法,该方法通过钯催化的N-(2-溴芳基)咔唑的环化反应来实现。该反应涉及分子内CC键的形成,以及咔唑环上CX键和CH键的断裂。引入具有给电子基团或吸电子基团的N-芳基核上的取代基,并评估了用于环化的不同反应因子。
Nonafluoro-<i>tert</i>-butoxylation of Diaryliodonium Salts
and scalability. In comparison with the conventional approach, this method avoids the use of nonafluoro-tert-butyl alcohol as the reaction solvent and does not require handling of hazardous diazonium salts. A series of OC(CF3)3-containing analogues of 19F NMR-based probes targeting various biologically relevant analytes are prepared.
开发了一种将九氟叔丁氧基结合到各种芳烃中的高效方法。在没有过渡金属催化剂且官能团耐受性和可扩展性良好的情况下,这种C-O交叉偶联反应可以顺利进行。与常规方法相比,该方法避免了使用九氟叔丁醇作为反应溶剂,并且不需要处理有害的重氮盐。制备了一系列针对各种生物相关分析物的19 F NMR基探针的一系列含OC(CF 3)3的类似物。
Rhodium-Catalyzed Intramolecular C−H Silylation by Silacyclobutanes
作者:Qing-Wei Zhang、Kun An、Li-Chuan Liu、Shuangxi Guo、Chenran Jiang、Huifang Guo、Wei He
DOI:10.1002/anie.201602376
日期:2016.5.17
Silacyclobutane was discovered to be an efficient C−H bond silylation reagent. Under the catalysis of RhI/TMS‐segphos, silacyclobutane undergoes sequential C−Si/C−H bond activations, affording a series of π‐conjugated siloles in high yields and regioselectivities. The catalytic cycle was proposed to involve a rarely documented endocyclic β‐hydride elimination of five‐membered metallacycles, which after
发现硅环丁烷是一种有效的CH键甲硅烷基化试剂。在Rh I / TMS-segphos的催化下,硅环丁烷经历了连续的C-Si / C-H键活化,从而以高收率和区域选择性提供了一系列π-共轭硅化物。有人提出催化循环涉及很少有文献记载的五元金属环的环内β-氢化物消除,在还原性消除后会产生能够进行CH活化的Si-Rh I物种。
Synthesis of Dibenzosiloles through Electrocatalytic Sila‐Friedel‐Crafts Reaction
for the preparation of dibenzosiloles was developed through intramolecular C−H/Si−H dehydrogenative coupling strategy starting from biarylhydrosilanes. Both electro-donating and electro-withdrawing substitution groups were tolerated for this transformation, and the desired dibenzosilole products could be obtained in moderate to excellent yields. A sila-Friedel-Crafts reaction mechanism was proposed
LOW VISCOSITY LOW VOLATILITY LUBRICATING OIL BASE STOCKS AND PROCESSES FOR PREPARING SAME
申请人:ExxonMobil Research and Engineering Company
公开号:US20170137734A1
公开(公告)日:2017-05-18
A composition that includes one or more compounds represented by the formula
R
1
—O—R
2
wherein R
1
is a substituted or unsubstituted aryl or polyaryl group having from about 4 to about 40 carbon atoms, and R
2
is a substituted or unsubstituted, linear or branched, alkyl group having from about 4 to about 40 carbon atoms. The composition has a viscosity (Kv
100
) from about 1 to about 10 cSt at 100° C. as determined by ASTM D-445, a viscosity index (VI) from about −100 to about 300 as determined by ASTM D-2270, and a Noack volatility of no greater than 50 percent as determined by ASTM D-5800. The disclosure also relates to a process for producing the composition, a lubricating oil base stock and lubricating oil containing the composition, and a method of reducing boundary friction and improving dispersancy of polar additives of a lubricating oil by using as the lubricating oil a formulated oil containing the composition.