Imidazole Transfer from 1,1'-Carbonyldimidazole and 1,1'-(Thiocarbonyl)diimidazole to Alcohols. A New Protocol for the Conversion of Alcohols to Alkylheterocycles.
The transfer of imidazole from 1,1'-carbonyldimidazole (CDI) and 1,1'-(thiocarbonyl)diimidazole in modest to excellent yields under mild conditions was observed with activated alcohols, unactivated alcohols generally providing the expected carbonylimidazole esters. Reasonable mechanisms for the transfer are proposed. 1,1'-Carbonyldi-1,2,4-triazole was found to work as well, providing a new heterocycle in good yield. Chemists should be aware of this reaction when treating benzylic, vinylogous benzylic, and benzhydryl alcohols with CDI-type reagents, expecting elimination of heterocycle rather than incorporation of heterocycle and elimination of CO(2).
Totleben
Michael J.
MJ
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556.
Freeman
Jeremiah P.
JP
Szmuszkovicz
Jacob
J