78594-13-5

Upstream product

• 104213-87-8 2,4-dimethylphenyl phenylpropynoate 
• 4214-28-2 1-iodo-2,4-dimethylbenzene 
• 536-74-3 phenylacetylene 
• 108-38-3 m-xylene 
• 71-43-2 benzene 
• 637-44-5 phenylpropyolic acid 
• 1226156-14-4 3-(2,4-dimethylphenyl)propiolic acid 
• 80-17-1 benzenesufonyl hydrazide 
• 583-70-0 1-bromo-2,4-dimethylbenzene 
• 78594-07-7 2-(2,4-Dimethyl-phenyl)-3-phenyl-cycloprop-2-enone 

Relevant academic research and scientific papers

Palladium-Catalyzed Decarboxylative Coupling Reactions of Propiolic Acid Derivatives and Arylsulfonyl Hydrazide

Arylsulfonyl hydrazides were employed as coupling partners for the decarboxylative coupling reaction of propiolic acid derivatives. When the reaction was conducted using Pd(TFA) 2 (1.0 mol%), dppp (1.0 mol%), and Cu(OAc) 2 (2.4 equiv

Pd(NHC)PEPPSI-diazonium salts: An efficient blend for the decarboxylative Sonogashira cross coupling reaction

An efficient N-heterocyclic carbene based Pd complex is described for the de-carboxylative Sonogashira coupling reaction with diazonium salts under ligand and co-catalyst free conditions. Pd(NHC)PEPPSI not only offers an air and moisture stable pre-cataly

Copper-free Sonogashira cross-coupling reactions catalyzed by an efficient dimeric C,N-palladacycle in DMF/H2O

Very small concentrations of a dimeric C,N-palladacycle were used as an efficient homogeneous catalyst for Sonogashira cross-coupling reactions between various aryl halides and phenylacetylene. The catalytic reactions were performed without the need for copper in DMF/H2O. This catalytic system shows excellent yields for aryl iodides and bromides and even in the case of aryl chlorides.

Steric effect of substituents in haloarenes on the rate of cross-coupling reactions

The relative reactivity of ortho- and para-methyl-substituted iodoarenes in the Sonogashira reaction and palladium-catalyzed methoxycarbonylation, as well as of similarly substituted bromoarenes in the Suzuki reactions and cobalt-catalyzed methoxycarbonylation, was studied. Introduction of a methyl group into the para position of aryl halide slows down the cross-coupling. o-Methylhaloarenes are less reactive in palladiumcatalyzed reactions as compared to both unsubstituted haloarene and para-substituted analog. The presence of a methyl group in the ortho position with respect to the reaction center accelerates cobalt-catalyzed methoxycarbonylation.

Highly efficient Pd/tetraphosphine catalytic system for copper-free sonogashira reactions of aryl bromides with terminal alkynes

In this study, an easily synthesized polydentate ligand N,N,N',N'-tetra(diphenylphosphinomethyl)-1,2-ethylenediamine (1) in combination with [Pd(C3H5)Cl]2 was found to be an active catalyst in copper-free Sonogashira reactions. Most substrates, including steric hindered phenyl bromides and heteroaryl bromides, could couple efficiently with terminal alkynes in the presence of low catalyst loading (0.1 mol%) and this catalytic system showed excellent functional group tolerance. The influence of water in this system was also preliminarily investigated via 31P NMR in situ; that is, appropriate water favors the reaction while excess hindered this reaction.

The effect of steric bulk in Sonogashira coupling reactions

The rates of Sonogashira coupling reactions using [Pd-PR3] complexes depend on a combination of the steric bulk of phosphines and substrates; however, below a critical cone angle of ca. 170° the catalytic activity drops drastically. The Royal S

Sonogashira coupling reaction with diminished homocoupling

(Matrix presented) The side product from homocoupling reaction of two terminal acetylenes in the Sonogashira reaction can be reduced to about 2% using an atmosphere of hydrogen gas diluted with nitrogen or argon. Terminal arylethynes, diarylethynes, and a few new arylpyridylethynes with donor substituents have been synthesized in very good yields. Comparative control experiments suggest that the homocoupling yield is determined by concentration of both catalyst and oxygen.

6-Endo-Dig vs. 5-Exo-Dig Ring Closure in o-Hydroxyaryl Phenylethynyl Ketones. A New Approach to the Synthesis of Flavones and Aurones

The aryl phenylpropynoates 3a-c, prepared by esterification of phenylpropynoic acid with the corresponding phenols, by means of N,N'-dicyclohexylcarbodiimide, give upon irradiation the o-hydroxyaryl phenylethynyl ketones 4a-c.The cyclization of these compounds in basic media follows two alternative pathways: 6-endo-dig ring closure, to give the flavones 8a-c, and /or 5-exo-dig ring closure , to give the aurones 9a-c.The predominance of one or the other cyclization mode is strongly influenced by the reaction conditions.Thus, the use of potassium carbonate in acetoneas cyclizing reagent favors the 6-endo-dig process, while the 5-exo-dig process becomes clearly enhanced when using sodium ethoxide or potassium carbonate in ethanol.The mechanistic implications of these facts are discussed within the framework of Baldwin's rules.From the preparative point of view, the above results disclose the synthetic possibilities of the key ketones 4 as precursors of flavones and aurones.