39597-28-9

Upstream product

• 186581-53-3 diazomethane 
• 39597-27-8 4-hydroxy-benzo[c]chromen-6-one 
• 518-10-5 5,6-dimethoxy-diphenic acid 
• 610-97-9 o-iodo-methyl-benzoic acid 
• 10365-98-7 3-methoxyphenylboronic acid 
• 38087-96-6 3'-methoxy-[1,1'-biphenyl]-2-carboxylic acid 
• 856993-57-2 3,4-dimethoxy-phenanthrene-9,10-dione 
• 475-80-9 aristolochic acid II 
• 109588-94-5 5,6-methylenedioxy-diphenic acid 
• 3580-57-2 6-nitro-phenanthro[3,4-d][1,3]dioxole 
• 138008-91-0 Diethyl-carbamic acid 3-methoxy-biphenyl-2-yl ester 
• 138008-93-2 2'-Hydroxy-3'-methoxy-biphenyl-2-carboxylic acid diethylamide 

Relevant academic research and scientific papers

Visible-Light-Induced Arene C(sp 2)-H Lactonization Promoted by DDQ and tert -Butyl Nitrite

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

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.

Microwave-assisted cyclization under mildly basic conditions: Synthesis of 6 h -benzo [c] chromen-6-ones and their 7,8,9,10-tetrahydro analogues

Aryl 2-bromobenzoates and aryl 2-bromocyclohex-1-enecarboxylates are cyclized by microwave irradiation in dimethylformamide in the presence of K2CO3 to give the corresponding 6H-benzo[c]chromen-6-ones and their 7,8,9,10-tetrahydro analogues, respectively, in 50-72% yields. Aryl 3-bromoacrylates are also converted into 2H-chromen-2-ones under the employed conditions.

Electrochemical Intramolecular C—H/O—H Cross-Coupling of 2-Arylbenzoic Acids

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

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

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.

NIS-mediated oxidative lactonization of 2-arylbenzoic acids for the synthesis of dibenzopyranones under metal-free conditions

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

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

Remote Directed Metalation of Biaryl o-Carbamates. Ring to Ring Carbamoyl Transfer Route to Biaryls, Dibenzopyranones, and the Natural Fluorenone Dengibsin

A new remote metalation, carbamoyl transfer process (Scheme I), is demonstrated and elaborated for the regiospecific synthesis of highly hindered biaryls, dibenzopyranones (Table I), and the naturally occurring fluorenone dengibsin (15).