Pd(II)-catalyzed hydroxyl-directed C-H olefination enabled by monoprotected amino acid ligands.
A novel Pd(II)-catalyzed ortho-C-H olefination protocol has been developed using spatially remote, unprotected tertiary, secondary, and primary alcohols as the directing groups. Mono-N-protected amino acid ligands were found to promote the reaction, and an array of olefin coupling partners could be used. When electron-deficient alkenes were used, the resulting olefinated intermediates underwent subsequent Pd(II)-catalyzed oxidative intramolecular cyclization to give the corresponding pyran products, which could be converted into ortho-alkylated alcohols under hydrogenolysis conditions. The mechanistic details of the oxidative cyclization step are discussed and situated in the context of the overall catalytic cycle.
Lu
Yi
Y
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Wang
Dong-Hui
DH
Engle
Keary M
KM
Yu
Jin-Quan
JQ
D000475:Alkenes / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008024:Ligands; D010165:Palladium / Q000737:chemistry*
D000475:Alkenes; D000596:Amino Acids; D006878:Hydroxides; D008024:Ligands; D010165:Palladium; D002244:Carbon; D006859:Hydrogen; C031356:hydroxide ion