- A deacetylation-diazotation-coupling sequence: Palladium-catalyzed C-C bond formation with acetanilides as formal leaving groups
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Acetanilides can be deacetylated and diazotized in situ, and subsequently used in Pd-catalyzed coupling reactions without isolation of the diazonium intermediate. Heck reactions, Suzuki crosscoupling reactions, and a Pd-catalyzed [2+2+1] cycloaddition hav
- Schmidt, Bernd,Berger, Rene
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- Series of tetraaryl spiro compounds and preparation and application methods thereof
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The invention discloses a series of tetraaryl spiro compounds and preparation and application methods thereof and relates to a method for synthesizing a series of tetraaryl spiro compounds through direct cycloaddition reaction between aromatic tertiary amines and diaryl acetylene under catalysis of palladium acetate. The preparation method comprises mixing the palladium acetate with correspondingaromatic tertiary amines, the diaryl acetylene, copper acetate monohydrate, phenanthroline and tetrafluoroboric acid at a molar ratio of 0.2:2:2:2:0.25:0.3, adding in methanol as the solvent, fillingargon into a reaction system, controlling the reaction temperature to be 100-120 DEG C, and 24 hours later, extracting the solvent from the reaction system, and performing separation through silica column chromatography to obtain corresponding products. During the reaction above, the double-molecule diaryl acetylene is interpolated into the para C-H bonds of the aromatic tertiary amines to producethe spiro compounds. The preparation method of the series of tetraaryl spiro compounds has the advantages of being high in substrate applicability, simple in substrate structure, easy to acquire andthe like.
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Paragraph 0025
(2019/04/17)
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- Pd-catalyzed [2+2+1] coupling of alkynes and arenes: Phenol diazonium salts as mechanistic trapdoors
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Alkynes and phenol diazonium salts undergo a Pd-catalyzed [2+2+1] cyclization reaction to spiro[4,5]decatetraene-7-ones. This structure was confirmed for one example by X-ray single-crystal structure analysis. The reaction is believed to proceed through oxidative addition of the phenol diazonium cation to Pd0, subsequent insertion of two alkynes, followed by irreversible spirocyclization. Copyright
- Schmidt, Bernd,Berger, Rene,Kelling, Alexandra,Schilde, Uwe
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supporting information; experimental part
p. 7032 - 7040
(2011/07/30)
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