Electronic Control of Chiral Quaternary Center Creation in the Intramolecular Asymmetric Heck Reaction
作者:Carl A. Busacca、Danja Grossbach、Scot J. Campbell、Yong Dong、Magnus C. Eriksson、Robert E. Harris、Paul-James Jones、Ji-Young Kim、Jon C. Lorenz、Keith B. McKellop、Erin M. O'Brien、Fenghe Qiu、Robert D. Simpson、Lana Smith、Regina C. So、Earl M. Spinelli、Jana Vitous、Chiara Zavattaro
DOI:10.1021/jo049448z
日期:2004.8.1
The Boehringer-Ingelheim phosphinoimidazoline (BIPI) ligands were applied to the formation of chiral quaternary centers in the asymmetric Heck reaction. Several different substrates were examined in detail, using more than 70 members of this new ligand class. Hammett relationships were determined through systematic variation of the ligand electronics. All substrates showed essentially the same Hammett behavior, where enantioselectivity increased as the ligands were made more electron-deficient. Ligand optimization has led to catalysts which give the highest enantioselectivities reported to date for these difficult systems.
Controlled Photochemical Synthesis of Substituted Isoquinoline-1,3,4(2<i>H</i>)-triones, 3-Hydroxyisoindolin-1-ones, and Phthalimides via Amidyl Radical Cyclization Cascade
We report a controlled radicalcyclizationcascade of isoquinoline-1,3,4(2H)-triones, 3-hydroxyisoindolin-1-ones, and phthalimides from o-alkynylated benzamides by metal-free photoredox catalyzed amidyl N-centered radicaladdition to the C–C triple bond using the proton-coupled electron transfer (PCET) process under mild reaction conditions. A time tunable synthesis of 3-hydroxyisoindolin-1-ones and