- Air-Tolerant Direct Thiol Esterification with Carboxylic Acids Using Hydrosilane via Simple Inorganic Base Catalysis
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Direct thioesterification of carboxylic acids with thiols using nontoxic activation agents is highly desirable. Herein, an efficient and practical protocol using safe and inexpensive industrial waste polymethylhydrosiloxane as the activation agent and K3PO4 with 18-crown-6 as a catalyst is described. Various functional groups on carboxylic acid and thiol substituents can be tolerated by the present system to afford thioesters in yields of 19-100%.
- Xuan, Maojie,Lu, Chunlei,Liu, Meina,Lin, Bo-Lin
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p. 7694 - 7701
(2019/06/27)
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- Equilibrium shift in the rhodium-catalyzed acyl transfer reactions
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Rhodium/phosphine complexes catalyze equilibrium acyl transfer reactions between acid fluorides, aryl esters, acylphosphine sulfides, and thioesters. The use of appropriate co-substrates to accept heteroatom groups shifted the equilibrium to desired products. Acylphosphine sulfides and aryl esters were converted to acid fluorides using benzoylpentafluorobenzene as the fluoride donor, and the fluorination reaction of thioesters employed (4-tolylthio) pentafluorobenzene. Acid fluorides were converted into acylphosphine sulfides and thioesters using diphosphine disulfides and disulfides/triphenylphosphine, respectively. Aryl esters were obtained from acid fluorides and phenols in the presence of triphenylsilane. Aryl esters, acylphosphine sulfides, and thioesters were also interconverted in the presence of rhodium complexes. These rhodium-catalyzed acyl transfer reactions proceeded under neutral conditions without using acid or base. The involvement of acyl rhodium intermediates in these reactions was suggested by the carbothiolation reaction of thioesters and alkynes.
- Arisawa, Mieko,Igarashi, Yui,Kobayashi, Haruki,Yamada, Toru,Bando, Kentaro,Ichikawa, Takuya,Yamaguchi, Masahiko
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p. 7846 - 7859
(2011/10/12)
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- Rhodium-catalyzed interconversion between acid fluorides and thioesters controlled using heteroatom acceptors
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A rhodium complex catalyzed the equilibrium acyl transfer reaction between acid fluorides and thioesters. In the presence of fluoride or thiolate acceptors, the reaction could be shifted to either product. RhH(PPh 3)4-dppe catalyzed the reaction of acid fluorides and diorgano disulfides in the presence of triphenylphosphine giving thioesters, which was accompanied by triphenylphosphine difluoride. The same complex catalyzed the reaction of aryl thioesters and hexafluorobenzene giving acid fluorides, which was accompanied by 1,4-di(arylthio)-2,3,5,6- tetrafluorobenzenes.
- Arisawa, Mieko,Yamada, Toru,Yamaguchi, Masahiko
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supporting information; experimental part
p. 6090 - 6092
(2011/01/04)
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