Tsutsui H,
Narasaka K.
*
The University of Tokyo, Japan
Synthesis of Pyrrole Derivatives by the Heck-Type Cyclization of γ,δ-Unsaturated Ketone
O-Pentafluorobenzoyloximes.
Chem. Lett. 1999;
28: 45-46
Key words
amino-Heck cyclization - oximes - palladium catalysis - pyrroles
Significance
Based on the finding that palladium(0) can cleave the N–O bond of sulfonyloximes, Tsutsui and Narasaka reported a catalytic protocol coupled with an intramolecular Heck-type cyclization to form pyrroles. Competing Beckmann rearrangement of the oxime derivatives could be suppressed by changing from the sulfonyl- to the pentafluorophenylacyl N-protecting group.
Comment
In the following years, this method was successfully extended to access various N-heterocycles (see Review below). An enantioselective version for the synthesis of dihydropyrroles bearing a stereogenic center at the 2-position was introduced by Bower and co-workers (Chem. Sci.
2017, 8, 1981).
Review
M. Kitamura, K. Narasaka Chem. Rec.
2002, 2, 268–277.
