99234-06-7Relevant academic research and scientific papers
Cycloadditions of Ketenes with Cyclic Carbodiimides
Brady, William T.,Shieh, C. H.
, p. 357 - 360 (2007/10/02)
The cycloaddition of ketenes with cyclic carbodiimides yields β-lactams in good to excellent yields.The cycloaddition of equal molar amounts of diphenyl-, phenylethyl- and phenylketenes with cyclic carbodiimides produced a 1:1 cycloaddition product, the expected β-lactams.However, the cycloaddition of 2:1 molar ratio of diphenyl- and phenylketenes with 1,3-diazacycloocta-1,2-diene respectively, gave the 2:1 cycloadducts, the tricyclodi-β-lactams.The cycloaddition of methylchloro- and dichloroketenes yielded β-lactams that were very susceptible to hydrolysis to the N-substituted cycloureas.A trapping experiment suggests that these reactions proceed through a stabilized dipolar intemediate.
