Rhodium-catalyzed rearrangement of alpha-diazo thiol esters to thio-substituted ketenes. Application in the synthesis of cyclobutanones, cyclobutenones, and beta-lactams.
Exposure of alpha-diazo thiol esters (1) to the action of catalytic rhodium(II) acetate leads to a remarkably facile "thia-Wolff rearrangement", producing thio-substituted ketenes which combine with a variety of ketenophiles to provide access to alpha-thiocyclobutanones, cyclobutenones, and beta-lactams. Reductive desulfurization of these cycloadducts takes place under mild conditions and in excellent yield, and this sequence thus represents a useful new alternative to the existing dichloroketene-based methodology for the synthesis of four-membered carbocycles and heterocycles.
Lawlor
M D
MD
Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139, USA.
Lee
T W
TW
Danheiser
R L
RL
D001391:Azo Compounds; D002384:Catalysis; D003503:Cyclobutanes / Q000138:chemical synthesis*; D015195:Drug Design; D004952:Esters; D005030:Ethylenes / Q000138:chemical synthesis / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D012238:Rhodium; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry; D047090:beta-Lactams / Q000138:chemical synthesis*
D001391:Azo Compounds; D003503:Cyclobutanes; D004952:Esters; D005030:Ethylenes; D007659:Ketones; D013438:Sulfhydryl Compounds; D047090:beta-Lactams; D012238:Rhodium; C008223:ketene