3701-38-0Relevant 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
, 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.
Cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids
Wadekar, Ketan,Aswale, Suraj,Yatham, Veera Reddy
supporting information, p. 983 - 987 (2020/02/15)
The first cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids has been developed. This operationally simple protocol allows rapid access to synthetically useful coumarins on gram scale by employing CeCl3 as a photocatalyst and O2 as a terminal oxidant. Overall, this delivers an economical and environmentally amiable entry to diversely substituted coumarins, important structural motifs in bioactive molecules.
Light-Driven Intermolecular Charge Transfer Induced Reactivity of Ethynylbenziodoxol(on)e and Phenols
Liu, Bin,Lim, Chern-Hooi,Miyake, Garret M.
supporting information, p. 12829 - 12835 (2018/10/15)
Ethynylbenziodoxol(on)es (EBXs) have been widely used in organic synthesis as electrophilic alkyne-transfer reagents involving carbon- and heteroatom-based nucleophiles. However, potential reactions of EBXs with phenols remain uninvestigated. Here, we present the formation of (Z)-2-iodovinyl phenyl ethers with excellent regio- and stereoselectivity through the reactivity between EBXs and phenols driven by visible light. We propose that this light-activated transformation proceeds through electron donor-acceptor complexes to enable new reactivity beyond existing mechanisms for alkynylation of carbon- and heteroatom-based nucleophiles. This operationally robust process was employed for the synthesis of diverse (Z)-2-iodovinyl phenyl ethers through irradiating a solution containing a phenyl-EBX, a phenol, and the base Cs2CO3 with a commercially available blue LED at room temperature. The (Z)-2-iodovinyl phenyl ether products can be further stereospecifically functionalized to form trisubstituted alkenes, demonstrating the potential of these products en route to chemical complexity.
Electrochemical Intramolecular C—H/O—H Cross-Coupling of 2-Arylbenzoic Acids
Shao, Ailong,Li, Na,Gao, Yong,Zhan, Jirui,Chiang, Chien-Wei,Lei, Aiwen
supporting information, p. 619 - 624 (2018/05/30)
A synthetic protocol to lactones by electro-oxidative induced C—H activation of 2-arylbenzoic acids has been developed. By using Na2SO4 aqueous solution as a cheap and green supporting electrolyte, different 2-arylbenzoic acids could provide the corresponding lactones in 30%—90% yields. This reaction could be conducted on a gram scale with a good efficiency as well as a high utility for natural product synthesis.
Tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
Yedage, Subhash L.,Bhanage, Bhalchandra M.
, p. 5769 - 5781 (2017/06/07)
This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.
Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids
Ramirez, Nieves P.,Bosque, Irene,Gonzalez-Gomez, Jose C.
, p. 4550 - 4553 (2015/09/28)
A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr+-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins. Preliminary mechanistic studies suggest that this reaction most likely occurs through a homolytic aromatic substitution pathway.
Mild ArI-catalyzed C(sp2)-H or C(sp3)-H functionalization/C-O formation: An intriguing catalyst-controlled selectivity switch
Wang, Xueqiang,Gallardo-Donaire, Joan,Martin, Ruben
supporting information, p. 11084 - 11087 (2015/03/30)
A tandem C(sp2)H and C(sp3)H functionalization/CO bond formation catalyzed by iodine(III) reagents generated in situ has been developed. The method shows wide scope under mild conditions and exhibits an unprecedented selectivity profile that can be switched depending on the catalyst employed.
NIS-mediated oxidative lactonization of 2-arylbenzoic acids for the synthesis of dibenzopyranones under metal-free conditions
Gao, Peng,Wei, Yunyang
supporting information, p. 343 - 347 (2014/02/14)
A series of dibenzopyranones were synthesized from 2-arylbenzoic acids by a radical oxidative cyclization procedure mediated by N-iodosuccinimide (NIS). The methodology is distinguished by its practicality in terms of its wide substrate scope, good functi
Cu-catalyzed mild C(sp2)-H functionalization assisted by carboxylic acids en route to hydroxylated arenes
Gallardo-Donaire, Joan,Martin, Ruben
supporting information, p. 9350 - 9353 (2013/07/25)
A formal Cu-catalyzed C(sp2)-H hydroxylation assisted by benzoic acids is described. The procedure is characterized by its mild reaction conditions and wide substrate scope utilizing simple and cheap Cu catalysts, thus becoming a user-friendly
