Regioselective synthesis of isocoumarins by ruthenium-catalyzed aerobic oxidative cyclization of aromatic acids with alkynes
作者:Ravi Kiran Chinnagolla、Masilamani Jeganmohan
DOI:10.1039/c2cc16916a
日期:——
The highly regioselective aerobic oxidative cyclization of aromatic, heteroaromatic and alkenyl acids with alkynes in the presence of catalytic amounts of [RuCl2(p-cymene)}2], AgSbF6 and Cu(OAc)2·H2O providing isocoumarin derivatives was investigated.
Five- and Six-Membered Nickelacyclic Carboxylates as Reagents for the Facile Synthesis of δ-Ketocarboxylic Acids, Isocoumarins, and 1,3-Dicarbonyl Derivatives of Benzoic Acid
The nickelacyclic carboxylates A and B reacted with α-halo ketones to form α,β-unsaturated δ-ketocarboxylic acids which were easily converted into pyranones or isocoumarins. In addition, reaction of the nickelacyclic acyl derivative C with α-halo ketones resulted in the formation of substituted 1,3-dicarbonyl compounds with a benzoic acid substituent in the 1-position. In these reactions, many functional groups were tolerated.
A simple and efficient palladium-catalyzed intramolecular carbonylativesynthesis of isocoumarins and phthalides from the easily available starting materials by employing phenylformate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.
One-Pot Sequential N-Heterocyclic Carbene/Rhodium(III) Catalysis: Synthesis of Fused Polycyclic Isocoumarins
作者:So Won Youn、Huen Ji Yoo
DOI:10.1002/adsc.201700072
日期:2017.7.3
A one‐pot sequential N‐heterocyclic carbene–rhodium (NHC‐Rh) catalysis is described, demonstrating the compatibility of NHC and Rh catalysts. N‐Heterocyclic carbene‐catalyzedaerobicoxidation of benzaldehydes and subsequent rhodium(III)‐catalyzedoxidative coupling/annulation with multiple bonds enabled the formation of two C–O bonds and one C–C bond in a single pot. This operationally easy, one‐pot
Rhodium- and Iridium-Catalyzed Oxidative Coupling of Benzoic Acids with Alkynes via Regioselective C−H Bond Cleavage
作者:Kenji Ueura、Tetsuya Satoh、Masahiro Miura
DOI:10.1021/jo070735n
日期:2007.7.1
coupling of benzoicacids with internal alkynes effectively proceeds in the presence of [Cp*RhCl2]2 and Cu(OAc)2·H2O as catalyst and oxidant, respectively, to produce the corresponding isocoumarin derivatives. The copper salt can be reduced to a catalytic quantity under air. Interestingly, by using [Cp*IrCl2]2 in place of [Cp*RhCl2]2, the substrates undergo 1:2 coupling accompanied by decarboxylation to afford