PCBs are absorbed via inhalation, oral, and dermal routes of exposure. They are trasported in the blood, often bound to albumin. Due to their lipophilic nature they tend to accumulate in lipid-rich tissues, such as the liver, adipose, and skin. Metabolism of PCBs is very slow and varies based on the degree and position of chlorination. PCBs are metabolized by the microsomal monooxygenase system catalyzed by cytochrome P-450 enzymes to polar metabolites that can undergo conjugation with glutathione and glucuronic acid. The major metabolites are hydroxylated products which are excreted in the bile and faeces. The slow metabolism of PCBs means they tend to accumulate in body tissues. (L4, T6)
The mechanism of action varies with the specific PCB. Dioxin-like PCBs bind to the aryl hydrocarbon receptor, which disrupts cell function by altering the transcription of genes, mainly be inducing the expression of hepatic Phase I and Phase II enzymes, especially of the cytochrome P450 family. Most of the toxic effects of PCBs are believed to be results of Ah receptor binding. Other PBCs are believed to interfere with calcium channels and/or change brain dopamine levels. PCBs can also cause endocrine disurption by altering the production of thyroid hormones and binding to estrogen receptors, which can stimulate the growth of certain cancer cells and produce other estrogenic effects, such as reproductive dysfunction. They will bioaccumulate by binding to receptor proteins such as uteroglobin. (A3, A4, A30, A66)
The most common health effects of PCBs are skin conditions such as chloracne and rashes. Chronic PCB exposure has also been shown to cause liver, stomach and kidney, damage, jaundice, edema, anemia, changes in the immune system, behavioral alterations, and impaired reproduction. (L4)
Raney Ni-Al合金在NaOH，KOH，CsOH，LiOH或Ca（OH）2或碱金属碳酸盐（如Na 2 CO 3，K 2 CO 3）的稀碱水溶液中成为一种非常有效的还原剂并脱氯多氯联苯（PCB）分别有效地产生了单氯联苯和二氯联苯，分别提供了联苯和/或苯基环己烷。反应在温和的条件下进行，无需使用有机溶剂。还研究了阮内镍铝合金在超声作用下对二氯联苯的还原脱氯作用。
Highly efficient palladium-catalyzed cross-coupling of diarylborinic acids with arenediazoniums for practical diaryl synthesis
作者：Fengze Wang、Chen Wang、Guoping Sun、Gang Zou
DOI：10.1016/j.tetlet.2019.151491
日期：2020.2
A highly efficient cross-coupling of cost-effective diarylborinic acids with both isolatable and latent arenediazoniums, i.e. tetrafluoroborates and aryltriazenes, respectively, has been developed with a practical palladium catalyst system under base-free conditions in open flask at room temperature. A variety of electronically and sterically various biaryls, in particular, those bearing a coordinative
Synthesis of Biaryls Using the Coupling Reaction of Diaryldimethyltins with Copper(II) Nitrate
作者：Genta Harada、Masato Yoshida、Masahiko Iyoda
DOI：10.1246/cl.2000.160
日期：2000.2
Cu(NO3)2·3H2O in THF proceeds smoothly at room temperature under ambient atmosphere to produce the corresponding biaryls in good to high yields. Diaryldimethyltins can be prepared in high yields by the reaction of aryllithiums with dichlorodimethyltin.
Single‐step oxidative homocoupling of aryl Grignard reagents via Co(II), Ni(II) and Cu(II) Complexes under air
作者：Aparna P. I. Bhat、Badekai Ramachandra Bhat
DOI：10.1002/aoc.3130
日期：2014.6
Cu(II) complexes has been developed. The reaction system involves in situ synthesis of Grignard reagents. The complexes, containing bidentate Schiff base and dmit (2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate) ligands, were compatible with diverse functionalities and afford a high yield of biaryls in a single step, proving to be promising catalysts in homocoupling reactions. Atmospheric oxygen is used as an oxidant
Nickel-Phosphine Complex-Catalyzed Grignard Coupling. I. Cross-Coupling of Alkyl, Aryl, and Alkenyl Grignard Reagents with Aryl and Alkenyl Halides: General Scope and Limitations
(s)), aryl, and alkenyl Grignard reagents and nonfused, fused, and substituted aromatic halides and haloolefins. Limitations lie in sluggish reactions between alkyl Grignard reagents and dihaloethylenes. The most effective catalysts are [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2] for alkyl and simple aryl Grignard reagents, [Ni(CH3)2P(CH2)2P(CH3)2}Cl2] for alkenyl and allylic Grignard reagents and [NiP(C6H5)3}2-Cl2]
已经确定，二卤代二膦镍 (II) 配合物对格氏试剂与芳基和链烯基卤化物的选择性交叉偶联表现出极高的催化活性。由于该催化反应程序简单、反应条件温和、偶联产物的收率和纯度高，以及广泛适用于涉及伯和仲烷基的反应（无论β-的存在与否），该催化反应可用于合成实践。氢 (s))、芳基和烯基格氏试剂以及非稠合、稠合和取代的芳族卤化物和卤代烯烃。限制在于烷基格氏试剂和二卤乙烯之间的缓慢反应。对于烷基和简单的芳基格氏试剂，最有效的催化剂是 [Ni(C6H5)2P(CH2)3P(C6H5)2}Cl2]，[Ni(CH3)2P(CH2)2P(CH3)2}Cl2] 用于烯基和烯丙基格氏试剂，[NiP(C6H5)3}2-Cl2] 用于空间位阻芳基格氏试剂和卤化物。膦配体对...的巨大稳定作用
palladium catalysed Ullmann biarylsynthesis has been developed using hydrazine hydrate as the reducing reagent at room temperature. The combination of Pd(OAc)2 and hydrazine hydrate works smoothly for the coupling of both electron-rich and electron-deficient aryl iodides, as well as hetero-aryl iodides, leading to a wide range of biaryls in good to excellent yields. The reaction requires only 1 mol% Pd(OAc)2
