Catalytic Synthesis of gamma-Lactams via direct annulations of enals and N-sulfonylimines.
[reaction: see text] Cinnamaldehydes and N-sulfonylimines undergo direct annulations to cis-disubstituted gamma-lactams via the intermediacy of catalytically generated homoenolates. Critical to the success of this process was overcoming inhibition of the N-heterocyclic carbene catalyst by the electrophilic imines. The overall process proceeds with good yields and diastereoselectivites and requires no stoichiometric reagents or additives.
Department of Chemistry and Biochemistry, University of California-Santa Barbara, 93101, USA.
Ming
M
He
Jeffrey W
JW
Bode