85679-03-4Relevant academic research and scientific papers
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.
Synthesis of substituted helicenes by Ir-catalyzed annulative coupling of biarylcarboxylic acid chlorides with alkynes
Kamikawa, Ken,Den, Hiroakira,Tsurusaki, Akihiro,Nagata, Tomoya,Miura, Masahiro
supporting information, p. 1069 - 1074 (2018/07/29)
A series of substituted [4] and [5]helicenes were synthesized in moderate to good yields by an Ir-catalyzed annulative coupling of biarylcarboxylic acid chlorides with internal alkynes, which involves facile C-H bond cleavage and decarbonylation. The double annulative coupling of 1, 1′:5′, 1″-ternaphthalene- 2, 2″-dicarboxylic acid dichloride with 4-octyne was also accomplished to give rise to an S-shaped double helicene. Unexpectedly, a π-extended benzofluoranthene-merged [5]- helicene was constructed through the annulative coupling and the successive C(aryl)-C(aryl) bond forming reaction when 1, 1′:4′, 1″-ternaphthalene-2, 2″-dicarboxylic acid dichloride was employed as the substrate. The crystal structure and the optical properties of the latter unique product were also investigated.
Differentially Substituted Phosphines via Decarbonylation of Acylphosphines
Yu, Rongrong,Chen, Xingyu,Martin, Stephen F.,Wang, Zhiqian
, p. 1808 - 1811 (2017/04/11)
A new route to phosphines was developed by a method that features a "pre-join and transform" process that proceeds via acylphosphine intermediates that may be readily prepared from carboxylic acids and disubstituted phosphines. The efficient decarbonylations of these acylphosphines using a nickel catalyst delivered the corresponding phosphines. This method shows that the carboxyl group can play a role similar to halides or triflates for introducing a substituted phosphorus atom on an aromatic ring.
Ruthenium(0)-Catalyzed C-H Arylation of Aromatic Imines under Neutral Conditions: Access to Biaryl Aldehydes
Hu, Feng,Szostak, Michal
, p. 4186 - 4189 (2016/09/09)
The first ruthenium(0)-catalyzed C-H bond arylation of aromatic imines with arylboronates under neutral conditions is reported. This versatile method provides rapid access to a wide range of biaryl aldehydes that are difficult to assemble using traditional methods with high atom economy. A new hydrogen acceptor for Ru(0) arylation has been identified. This atom-economical strategy has potential for an array of direct applications in Ru(0)-catalyzed C-H bond arylations using removable directing groups. An indole synthesis by a sequential one-pot, multiple C-H activation protocol is reported.
Ortho-lithium/magnesium carboxylate-driven aromatic nucleophilic substitution reactions on unprotected naphthoic acids
Aissaoui, Regadia,Nourry, Arnaud,Coquel, Ariane,Dao, Thi Thanh Ha,Derdour, Aicha,Helesbeux, Jean-Jacques,Duval, Olivier,Castanet, Anne-Sophie,Mortier, Jacques
experimental part, p. 718 - 724 (2012/02/16)
Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good to excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO 2H) group. This novel nucleophilic aromatic substitution is presumed to proceed via a precoordination of the organometallic with the substrate, followed by an addition/elimination.
METHOD FOR PREPARING CHEMICAL COMPOUNDS OF INTEREST BY NUCLEOPHILIC AROMATIC SUBSTITUTION OF AROMATIC CARBOXYLIC ACID DERIVATIVES SUPPORTING AT LEAST ONE ELECTRO-ATTRACTIVE GROUP
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Page/Page column 17, (2013/02/27)
Method for preparing carboxylic acid derivatives by aromatic nucleophilic substitution, in which a carboxylic acid derivative having a single carboxyl functional group, or one of the salts thereof, the carboxylic acid derivative having, in the ortho posit
Syndiospezifische polymerisation von propylen: 3-, 4-, 3,4-und 4,5-substituierte zirkonocenkomplexe des typs (C13H8-nRnCR′2C5H4)ZrCl2 (n = 1, 2; R = alkyl, aryl; R′ = Me, Ph)
Alt, Helmut G.,Zenk, Roland,Milius, Wolfgang
, p. 257 - 270 (2007/10/03)
Substituents in the positions 3, 4, 5 and 6 of the fluorenylidene fragment clearly influence the polymerization behaviour of the syndiospecific catalyst systems (C13H8-nRnCR′2C5H4)ZrCl2/MAO (n = 1, 2; R = alkyl, aryl; R′ = Me, Ph). We report seven new catalyst precursors of this type, including first polymerization results. An X-ray study of the 4,5-dimethyl derivative 10b explains the reduced activity and stereospecifity of this catalyst.
