Shimazumi R,
Tanimoto R,
Kodama T,
Tobisu M.
*
Osaka University, Japan
Palladium-Catalyzed Unimolecular Fragment Coupling of
N-Allylamides via Elimination of Isocyanate.
J. Am. Chem. Soc. 2022;
144: 11033-11043
DOI:
10.1021/jacs.2c04527
Key words
amides - isocyanate elimination - palladium catalysis - unimolecular fragment coupling
Significance
A palladium(0)-catalyzed unimolecular fragment coupling (UFC) reaction of N-allyl amides through the elimination of an isocyanate is reported. Recombination
of the resulting fragments leads to C–N, C–C, and C–S bond formation in good to high
yields. The synthetic value of this protocol is highlighted by the late-stage conversion
of amides into allyl groups.
Comment
Besides Pd(PPh3)4, Ni(cod)2 can also be used as the catalyst. Several control experiments under palladium catalysis
were performed, supporting the shown mechanism. The use of nickel as transition metal
eventually allowed the crystallographic characterization of the cationic π-allyl intermediate.
