188943-06-8Relevant articles and documents
Dual Nickel-/Palladium-Catalyzed Reductive Cross-Coupling Reactions between Two Phenol Derivatives
Xiong, Baojian,Li, Yue,Wei, Yin,Kramer, S?ren,Lian, Zhong
supporting information, p. 6334 - 6338 (2020/09/02)
Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance of phenols. Here, we report a dual nickel-/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2′-disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allows for straightforward late-stage functionalization, illustrated with examples such as ezetimibe and tyrosine.
Visible-Light-Induced Arene C(sp 2)-H Lactonization Promoted by DDQ and tert -Butyl Nitrite
Chen, Bajin,Hu, Baoxiang,Hu, Xinquan,Jin, Liqun,Li, Meichao,Shen, Zhenlu,Sun, Nan,Wang, Shengpeng,Wang, Yiqing
supporting information, p. 261 - 266 (2020/02/18)
A visible-light photocatalytic aerobic oxidative lactonization of arene C(sp 2)-H bonds proceeds in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert -butyl nitrite (TBN). Under the optimized conditions, a range of 2-arylbenzoic acids is converted into the corresponding benzocoumarin derivatives in moderate to excellent yields. This method is characterized by its atom economy, mild reaction conditions, the use of a green oxidant and metal-free catalysis.
Exploration of Biaryl Carboxylic Acids as Proton Shuttles for the Selective Functionalization of Indole C-H Bonds
Pi, Jing-Jing,Lu, Xiao-Yu,Liu, Jing-Hui,Lu, Xi,Xiao, Bin,Fu, Yao,Guimond, Nicolas
, p. 5791 - 5800 (2018/05/14)
A survey of diversely substituted 2-arylbenzoic acids were synthesized and tested for use as proton shuttle in the direct arylation of indoles with bromobenzenes. It was found that 3-ethoxy-2-phenylbenzoic acid gives superior yield and selectivity for this class of substrates.
Electronic effects on the substitution reactions of benzhydrols and fluorenyl alcohols. Determination of mechanism and effects of antiaromaticity
George, Stephen R. D.,Elton, Timothy E.,Harper, Jason B.
supporting information, p. 10745 - 10750 (2015/11/17)
A range of substituted benzhydrols and fluorenols were prepared and subjected to acid catalysed methanolysis. Analysis of the rates of each of these processes showed correlation with Hammett σ+ parameters as is consistent with the significant build-up of positive charge adjacent to the ring. In combination with the similarity of the electronic susceptibility of the processes, these data suggest that both reactions proceed through a unimolecular rate-determining step. This shows that the effect of fusion of the phenyl systems (and hence potentially introducing an antiaromatic carbocation intermediate) is only to slow the rate of reaction rather than change the mechanism of the process.
Synthesis of fluorenones through rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids
Fukuyama, Takahide,Maetani, Shinji,Miyagawa, Kazusa,Ryu, Ilhyong
supporting information, p. 3216 - 3219 (2014/07/08)
An efficient approach to the synthesis of fluorenones via the rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids was developed. Using this procedure, fluorenones with various substituents can be synthesized in good to high yields. This work marks the first recorded use of catalytic intramolecular acylation to synthesize fluorenones.
Synthesis of unsymmetrically substituted biaryls via sequential lithiation of dibromobiaryls using integrated microflow systems
Nagaki, Aiichiro,Takabayashi, Naofumi,Tomida, Yutaka,Yoshida, Jun-Ichi
supporting information; experimental part, (2010/04/22)
A microflow system consisting of micromixers and microtube reactors provides an effective method for the introduction of two electrophiles onto dibromobiaryls. Selective monolithiation of dibromobiaryls, such as 2,2'-dibromobiphenyl, 4,4'-dibromobiphenyl, 2,7-dibromo-9,9-dioctylfluorene, 2,2'-dibromo-1,1'-binaphthyl, and 2,2'-dibromobibenzyl with 1 equiv of n-butyllithium followed by the reaction with electrophiles was achieved using a microflow system by virtue of fast micromixing and precise temperature control. Sequential introduction of two different electrophiles was achieved using an integrated microflow system composed of four micromixers and four microtube reactors to obtain unsymmetrically substituted biaryl compounds.
An improved protocol for ligandless Suzuki-Miyaura coupling in water
Korolev, Dmitrii N.,Bumagin, Nikolay A.
, p. 4225 - 4229 (2007/10/03)
Using a reverse order of addition of reagents, PdCl2 and Pd(OAc)2 are efficient catalysts for the Suzuki-Miyaura reactions in water. The ligandless and mild conditions, the high stability of the catalytic system, short reaction time and good to excellent yields are important features of this protocol.
Nonpeptide arginine vasopressin antagonists for both V(1A) and V2 receptors: Synthesis and pharmacological properties of 2-Phenyl-4'- [(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]benzanilide derivatives
Matsuhisa, Akira,Tanaka, Akihiro,Kikuchi, Kazumi,Shimada, Yoshiaki,Yatsu, Takeyuki,Yanagisawa, Isao
, p. 1870 - 1874 (2007/10/03)
A series of compounds structurally related to 4'-[(2,3,4,5-tetrahydro- 1H-1-benzazepin-1-yl)carbonyl]benzanilide was synthesized and demonstrated to have arginine vasopressin (AVP) antagonist activity for both V(1A) and V2 receptors. The introduction of a phenyl or a 4-substituted phenyl group into the ortho position of the benzoyl moiety resulted in an increase in both binding affinity and antagonistic activity. The 2-(4-methylphenyl) derivative (1g) exhibited high antagonistic activities for both V(1A) (8.6- fold) and V2 (38-fold) receptors and high oral activity (8.6-fold) compared with the 2-methyl lead compound (1a). Detail of the synthesis and the pharmacological properties of this series are presented.
