22321-94-4

Upstream product

• 108-24-7 acetic anhydride 
• 75-36-5 acetyl chloride 
• 117-99-7 2-Hydroxybenzophenone 
• 673-32-5 1-Phenylprop-1-yne 
• 533-58-4 2-Iodophenol 
• 201230-82-2 carbon monoxide 
• 122059-77-2 2-[2-(2-Methoxymethoxy-phenyl)-1-methyl-2-phenyl-1-phenylsulfanyl-ethyl]-4,4-dimethyl-4,5-dihydro-oxazole 
• 2553-04-0 ortho-methoxybenzophenone 
• 1187250-79-8 C₁₆H₁₆O₂ 
• 100-52-7 benzaldehyde 
• 122059-67-0 4,4-Dimethyl-2-((E)-2-phenyl-1-phenylsulfanyl-vinyl)-4,5-dihydro-oxazole 

Relevant academic research and scientific papers

Synthesis of coumarins catalyzed by heterobimetallic Co/Rh nanoparticles

Described here is the use of cobalt/rhodium (CO2Rh2) heterobimetallic nanoparticles in the catalytic synthesis of coumarins via cyclocarbonylation of alkynes with 2-iodophenol under 1 atm of carbon monoxide and reaction of phenol wit

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.

Rhodium(I)-Catalyzed Decarbonylative Aerobic Oxidation of Cyclic α-Diketones: A Regioselective Single Carbon Extrusion Strategy

A rhodium-catalyzed decarbonylative aerobic oxidation of cyclic α-diketones has been developed for the first time, where the regioselective formations of α-pyrones and isocoumarins have been achieved. The current decarbonylative aerobic oxidation pathway proceeds via the C-C bond cleavage followed by a C-O bond formation, representing a biomimetic oxidation approach to unsaturated six-membered cyclic lactones. The unique ability of rhodium catalysts to induce the decarbonylative aerobic oxidation opens up a new synthetic toolbox that utilizes the "regioselective single carbon" extrusion strategy.

Expedient synthesis of highly substituted α-pyrones from Baylis-Hillman adducts and their conversion to poly-substituted aromatics

An efficient synthetic protocol of fully substituted α-pyrones has been developed starting from the Baylis-Hillman adducts. Subsequent Diels-Alder reaction of the α-pyrones and DMAD produced poly-substituted aromatic compounds in high yields.

Palladium-Catalyzed Carbonylative Annulation of Internal Alkynes: Synthesis of 3,4-Disubstituted Coumarins

The palladium-catalyzed annulation of internal alkynes by o-iodophenols in the presence of CO results in exclusive formation of coumarins. No isomeric chromones have been observed. The best reaction conditions utilize the 2-iodophenol, 5 equiv of alkyne, 1 atm of CO, 5 mol% Pd(OAc)2, 2 equiv of pyridine, and 1 equiv of n-Bu4NCl in DMF at 120°C. The use of a sterically unhindered pyridine base is essential to achieve high yields. A wide variety of 3,4-disubstituted coumarins containing alkyl, aryl, silyl, alkoxy, acyl, and ester groups have been prepared in moderate to good yields. Mixtures of regioisomers have been obtained when unsymmetrical alkynes are employed. 2-Iodophenols with electron-withdrawing and electron-donating substituents and 3-iodo-2-pyridone are effective in this annulation process. The reaction is believed to proceed via (1) oxidative addition of the 2-iodophenol to Pd(0), (2) insertion of the alkyne triple bond into the aryl-palladium bond, (3) CO insertion into the resulting vinylic carbon-palladium bond, and (4) nucleophilic attack of the phenolic oxygen on the carbonyl carbon of the acylpalladium complex with simultaneous regeneration of the Pd(0) catalyst. This annulation process is the first example of intermolecular insertion of an alkyne occurring in preference to CO insertion.

Synthesis of coumarins via palladium-catalyzed carbonylative annulation of internal alkynes by o-lodophenols

(matrix presented) A variety of substituted coumarins have been prepared in good yields by the palladium-catalyzed coupling of o-iodophenols with internal alkynes and 1 atm of carbon monoxide. Unlike most of the previous work on the palladium-catalyzed carbonylation of alkynes, the insertion of the internal alkyne occurs in preference to the insertion of CO.

CONJUGATE ADDITIONS ON α-PHENYLTHIO-α,β-UNSATURATED OXAZOLINES. NOVEL SYNTHESIS OF 3,4-DISUBSTITUTED COUMARINS.

Nucleophilic addition of organolithium, Grignard and hydride reagents to α-phenylthio-α,β-unsaturated oxazolines is regioselective and occurs in a 1,4-fashion.This leads to a novel, versatile synthesis of polysubstituted coumarins.

A General Synthesis of 3,4-Disubstituted Coumarins

The complex of POCl3 and the substituted N,N-diethylacetamide is condensed with substituted o-hydroxy-acetophenones and -benzophenones to afford 3,4-disubstituted coumarins (1a-k).