| Autor: |
Thornbury RT; Department of Chemistry , University of California , Berkeley , California 94720 , USA . Email: fdtoste@berkeley.edu., Saini V; Novartis Institutes for Biomedical Research , Cambridge , Massachusetts 02139 , USA., Fernandes TA; Department of Chemistry , University of California , Berkeley , California 94720 , USA . Email: fdtoste@berkeley.edu.; Instituto de Química , Universidade de Brasília , Campus Universitário Darcy Ribeiro , Caixa Postal: 04478 , 70904-970 , Brasília , DF , Brazil., Santiago CB; Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , USA., Talbot EPA; Department of Chemistry , University of California , Berkeley , California 94720 , USA . Email: fdtoste@berkeley.edu.; Novartis Institutes for Biomedical Research , Cambridge , Massachusetts 02139 , USA., Sigman MS; Department of Chemistry , University of Utah , Salt Lake City , Utah 84112 , USA., McKenna JM; Novartis Institutes for Biomedical Research , Cambridge , Massachusetts 02139 , USA., Toste FD; Department of Chemistry , University of California , Berkeley , California 94720 , USA . Email: fdtoste@berkeley.edu. |
| Abstrakt: |
A mild palladium-catalyzed ligand-controlled regioselective 1,3-arylfluorination of 2[ H ]-chromenes has been developed. The products with a syn -1,3 substitution pattern were obtained with high enantiomeric excess using a PyrOx ligand, wherein the utility of these pyranyl-fluorides was further demonstrated through their participation in a diastereoselective C-C bond forming reaction. Ligand dependent divergent formation of both the 1,3- and 1,2- alkene difunctionalization products was observed. The nature of this bifurcation was investigated through experimental studies in combination with computational and statistical analysis tools. Ultimately, the site selectivity was found to rely on ligand denticity and metal electrophilicity, the electronics of the boronic acid, and the donor ability of the directing group in the substrate. |
