多环芳烃 (PAH),例如苯并 [ a ] 芘 (B a P),是普遍存在的环境污染物,与导致肺癌有关。B a P 是烟草烟雾的一种成分,通过酶促转化为与 DNA 相互作用的活性形式。我们之前报道了一种用于分析 B a P 代谢物的灵敏的稳定同位素稀释 LC/MS 方法的开发。我们现在报告了13 C 4 -B a P 的有效合成及其完整的13 C 4标记氧化代谢物,需要作为内标。它们包括不参与致癌作用的代谢物(A 组))和与癌症发生有关的代谢物(B组)。该合成方法是新颖的,需要使用 Pd 催化的 Suzuki、Sonogashira 和 Hartwig 交叉偶联反应与 PtCl 2催化的炔属化合物环化反应相结合。这种合成方法需要更少的步骤,使用更温和的条件,并且产物分离比传统的 PAH 合成方法更简单。13 C 4 -B a P 和13 C 4 -B a P-8-ol的合成各只需要四步,并且13
Gold-Catalyzed Annulation/Fragmentation: Formation of Free Gold Carbenes by Retro-Cyclopropanation
摘要:
The gold(I)-catalyzed cyclization of 1-(prop-2-yn-1-yl)-2-alkenylbenzenes substituted at the benzylic position with OR groups gives 1,3-disubstituted naphthalenes with concomitant fragmentation of the alkene. One of these annulations proceeds by a retro-cyclopropanation that leads to free gold(I) carbenes.
NAPHTHALENE DERIVATIVE, MATERIAL FOR ORGANIC ELECTROLUMINESCENCE DEVICE, AND ORGANIC ELECTROLUMINESCENCE DEVICE USING THE SAME
申请人:Kawamura Masahiro
公开号:US20090008605A1
公开(公告)日:2009-01-08
A naphthalene derivative represented by the following formula (1) is provided. In the formula, Ar
1
to Ar
4
each represent an aromatic hydrocarbon cyclic group having 6 to 18 carbon atoms forming a ring. The aromatic hydrocarbon cyclic group has none of anthracene skeleton, pyrene skeleton, aceanthrylene skeleton and naphthacene skeleton. n, m and 1 each represent an integer in a range of 1 to 5. p represents an integer in a range of o to 5. When n, m, 1 and p each are 2 or more, a plurality of Ar
1
to Ar
4
may be mutually the same or different.
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。
Ag‐Catalyzed Cyclization of Arylboronic Acids with Elemental Selenium for the Synthesis of Selenaheterocycles
A general method for the synthesis of five‐membered and six‐membered selenaheterocycles through Ag‐catalyzed C−Se bond‐forming reaction is reported. This reaction proceeds via intramolecular cyclization of arylboronic acids with selenium powder. Preliminary mechanism studies demonstrate that this transformation involves a selenium‐centred radical intermediate.
9-Silafluorenes via Base-Promoted Homolytic Aromatic Substitution (BHAS) – The Electron as a Catalyst
作者:Dirk Leifert、Armido Studer
DOI:10.1021/ol503574k
日期:2015.1.16
Transition-metal-free intramolecular radicalsilylation of 2-diphenylsilylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenylsilylbiaryls are readily prepared, and cross dehydrogenativesilylation occurs with tert-butylhydroperoxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetrabutylammonium iodide (TBAI)
A visible‐light inducedradicalsilylation to dibenzosiloles from biarylhydrosilanes is described. The products were obtained in satisfactory yields under mild and water/air compatible conditions, providing an efficient and practical method for the synthesis of difunctionalized siloles by using a cheap organic dye photocatalyst. The method is tolerated by a wide range of functional groups and has a