Surprisingly mild "enolate-counterion-free"pd(0)-catalyzed intramolecular allylic alkylations.
[reaction: see text] Palladium-catalyzed intramolecular allylic alkylations of unsaturated EWG-activated amides can take place under phase-transfer conditions or in the presence of a crown ether. These new reaction conditions are milder and higher yielding than those previously reported. A rationalization for such an unexpected result is put forth and validated by DFT-B3LYP calculations. The results suggest cyclization via a counterion-free (E)-enolate TS.
Madec
David
D
Université Pierre et Marie Curie, UMR 7611 CNRS, 4 Place Jussieu, Tour 44-45, Boîte 183, F-75252, Paris, Cedex 05, France.
Prestat
Guillaume
G
Martini
Elisabetta
E
Fristrup
Peter
P
Poli
Giovanni
G
Norrby
Per-Ola
PO