Pd(II)-Catalyzed Enantioselective C–H Activation/C–O Bond Formation: Synthesis of Chiral Benzofuranones
摘要:
Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.
Imidazole Derivatives as Accelerators for Ruthenium-Catalyzed Hydroesterification and Hydrocarbamoylation of Alkenes: Extensive Ligand Screening and Mechanistic Study
Imidazolederivatives are effective ligands for promoting the [Ru3(CO)12]‐catalyzed hydroesterification of alkenes using formates. Extensiveligandscreening was performed to identify 2‐hydroxymethylated imidazole as the optimal ligand. Neither carbon monoxide gas nor a directing group was required, and the reaction also showed a wide substrate generality. The Ru–imidazole catalyst system also promoted
Imidazole derivatives are revealed to be effective ligands in the Ru-catalyzed hydroesterification of alkenes using formates, affording one-carbon-elongated esters in high yields. Further, intramolecular hydroesterification was successfully performed to give lactones for the first time. Imidazole derivatives can contribute to promote the reaction as well as to suppress the undesired decarbonylation of formate. Toxic CO gas, a directing group, and large excess alkenes are not required.
Pd(II)-Catalyzed Enantioselective C–H Activation/C–O Bond Formation: Synthesis of Chiral Benzofuranones
Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.
Axially Chiral 1,1'‐Binaphthyl‐2‐Carboxylic Acid (BINA‐Cox) as Ligands for Titanium‐Catalyzed Asymmetric Hydroalkoxylation
作者:Sebastian L. Helmbrecht、Johannes Schlüter、Max Blazejak、Lukas Hintermann
DOI:10.1002/ejoc.201901895
日期:2020.4.16
1'‐biaryl‐2‐carboxylic acids, a catalyst for the asymmetric addition of phenolic hydroxyl to non‐activated alkene at hightemperature (240 °C) is formed. This work systematically develops scalable syntheses of variably decorated, enantiopure 1,1'‐biaryl‐2'‐carboxylic acids, which are then tested as steering ligands in intramolecular asymmetric catalytic hydroalkoxylation reactions.