A Kinetic Study on Nucleophilic Displacement Reactions of Aryl Benzenesulfonates with Potassium Ethoxide: Role of K<sup>+</sup> Ion and Reaction Mechanism Deduced from Analyses of LFERs and Activation Parameters
more reactive than the dissociated EtO–, indicating that K+ ion catalyzes the reaction. The catalytic effect exerted by K+ ion (e.g., the kEtOK/kEtO– ratio) decreases linearly as the substituent X in the benzenesulfonyl moiety changes from an electron-donating group (EDG) to an electron-withdrawing group (EWG), but it is independent of the electronic nature of the substituent Y in the leaving group
Pseudofirst一级速率常数(ķ实测值)已经被分光光度法测量为2,4-二硝基苯基X取代的苯磺酸盐的亲核取代反应4A - ˚F和Y取代的苯基苯磺酸5A - ķ在无水乙醇中与EtOK。的解剖ķ实测值成ķ环氧乙烷-和ķ EtOK(即,二阶速率常数,用于与离解的环氧乙烷的反应中-和离子配对分别EtOK,)示出了离子配对EtOK比离解的环氧乙烷反应性更强–,表示K+离子催化反应。随着苯磺酰基部分中的取代基X从给电子基团(EDG)变为吸电子基团(EWG),K +离子产生的催化作用(例如,k EtOK / k EtO –比)线性降低,但是它与离去基团中取代基Y的电子性质无关。通过线性自由能关系对动力学数据进行分析,得出了通过协调机制进行反应的结论(例如,Brønsted型,Hammett和Yukawa-Tsuno图)。钾+离子通过通过环状过渡态(TS)增加反应中心的亲电子性而不是通过增加离去基团的
FLUORENE-TYPE COMPOUND, PHOTOPOLYMERIZATION INITIATOR COMPRISING SAID FLUORENE-TYPE COMPOUND, AND PHOTOSENSITIVE COMPOSITION CONTAINING SAID PHOTOPOLYMERIZATION INITIATOR
申请人:Daito Chemix Corporation
公开号:US20150259321A1
公开(公告)日:2015-09-17
According to an embodiment of the present invention, there is provided a novel fluorene-based compound and a photopolymerization initiator using the fluorene-based compound. The fluorene-based compound according to an embodiment of the present invention is represented by the general formula (1). A photopolymerization initiator having additionally high sensitivity can be provided by using the fluorene-based compound. In addition, a photopolymerization initiator that can impart additionally excellent characteristics can be provided by appropriately selecting, for example, a substituent.
Site-Specific Oxidation of (sp<sup>3</sup>)C–C(sp<sup>3</sup>)/H Bonds by NaNO<sub>2</sub>/HCl
作者:Jianyou Zhao、Tong Shen、Zhihui Sun、Nengyong Wang、Le Yang、Jintao Wu、Huichao You、Zhong-Quan Liu
DOI:10.1021/acs.orglett.1c01303
日期:2021.5.21
(sp3)C–C(sp3) and (sp3)C–H bonds in aryl alkanes by the use of NaNO2/HCl was explored. The method is chemical-oxidant-free, transition-metal-free, uses water as the solvent, and proceeds under mild conditions, making it valuable and attractive to syntheticorganicchemistry.
A pyridine-bridged bis-benzimidazolylidene pincer nickel(ii) complex: synthesis and practical catalytic application towards Suzuki–Miyaura coupling with less-activated electrophiles
A novel robust pyridine-bridgedbis-benzimidazolylidene nickel pincercomplex 3 accessible from inexpensive, commercially available precursors efficiently catalyzes the first practical Suzuki-Miyaura cross-coupling reactions with various less-reactive electrophiles ArX (X = Br, Cl, OTs and OMs) and even tolerates electron-rich, sterically demanding and heterocyclic arenes in the presence of catalytic
Reactions of Carbanions with 1,3-Benzodioxin-4-ones: Facile Routes to Flavones, Aurones, and Acyl Phloroglucinols
作者:George Kraus、Jingqiang Wie、Aniket Thite
DOI:10.1055/s-2008-1078597
日期:2008.8
Two 1,3-benzodioxin-4-ones react with enolates, acetylides and aryllithium reagents to afford adducts that were converted into flavones, aurones, and an acyl phloroglucinol.