Abstract
Regioselectivity of selenium-mediated carbonylation of organolithium compounds with carbon monoxide has been investigated. The reactions of lithium enolates of 2,2-dicyclohexyl aldehyde and 1,1-dicyclohexylpropane-2-one with selenium and carbon monoxide afforded the corresponding selenocarbonates by carbonylation at the enolate oxygen as the main product. Carbonylation of nitrogen-containing heterocycles can give either C- or N-carbonylation product, but diphenyl(4-pyridyno)methane, imidazole, and pyrazole afford only corresponding carbamoselenoates via N-carbonylation.
Acknowledgments
Dedicated to Professor Naomichi Furukawa on the occasion of his 70th birthday.