Rhodium(I)-catalyzed allenic carbocyclization reaction affording delta- and epsilon-lactams.
This letter extends the scope of the rhodium(I)-catalyzed allenic Alder-ene carbocyclization reaction to the preparation of delta- and epsilon-lactams from amides. A variety of allenic propiolamides were cycloisomerized to give a number of unsaturated delta-lactams. In addition, allenic propargylamides give good yields of the corresponding epsilon-lactams. Formation of lactams possessing these ring sizes has rarely been accomplished via transition-metal-catalyzed carbon-carbon bond forming strategies. Thus, this approach provides an alternative strategy for synthesizing these substructures. [reaction: see text].
Brummond
Kay M
KM
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. kbrummon@pitt.edu
Painter
Thomas O
TO
Probst
Donald A
DA
Mitasev
Branko
B
D000466:Alkadienes / Q000138:chemical synthesis* / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
D000466:Alkadienes; D000475:Alkenes; D000480:Alkynes; D007769:Lactams; D012238:Rhodium