The versatile preparation of new anionic water-soluble ligands derived from triphenylphosphane is described based on halogen-lithium exchange followed by CO2 quenching. Efficient inter- and intramolecular Heck reactions have been disclosed. Comparison with other anionic and cationic ligands showed that meta substitution on the aromatic ring enhanced the reactivity.
A series of 3,3′-disubstituted BINAP ligands are used in asymmetric inter- and intramolecular Heck/Mizoroki reactions and their enantioselectivity compared to BINAP.
Synthesis of Spirocyclic Piperidines by Radical Hydroarylation
作者:Racheal M. Spurlin、Amber L. Harris、Nathan T. Jui、Cameron J. Pratt
DOI:10.1055/a-1315-1014
日期:2021.1
Reported here are conditions for the construction of spirocyclic piperidines from linear arylhalide precursors. These conditions employ a strongly reducing organic photoredox catalyst in combination with a trialkylamine reductant to achieve formation of aryl radical species. Regioselective cyclization followed by hydrogen-atom transfer affords a range of complex spiropiperidines. This system operates
The Application of HETPHOX Ligands to the Intramolecular Asymmetric Heck Reaction
作者:Patrick Guiry、Martin Fitzpatrick、Anthony Coyne
DOI:10.1055/s-2006-951500
日期:2006.11
A new thiophene-oxazoline P,N ligand derived from cis-aminoindanol was prepared and a range of analogous HETPHOX ligands were applied to the intramolecular Heck reaction. The enantioselectivity obtained was 76% employing the tert-butyl-substituted HETPHOX ligand with an aryl triflate spirooxindole precursor. The isomer distribution of the product spirooxindoles was high (up to 99:1).
Cobalt(<scp>II</scp>) Chloride–Grignard reagent: an alternative to tin hydride in aryl radical cyclisations
作者:Andrew J. Clark、David I. Davies、Keith Jones、Christopher Millbanks
DOI:10.1039/c39940000041
日期:——
Reaction of N-methyl, N-acryloyl-2-haloanilines with anhydrous cobalt(II) chloride and a Grignard reagent leads to formation of indol-2(3H)-ones via a reductive aryl radical cyclisation.