Article ISI
Helvetica Chimica Acta  (2014)

How small amounts of impurities are sufficient to catalyze the interconversion of carbonyl compounds and iminium ions, or is there a metathesis through 1,3-oxazetidinium ions? Experiments, speculations, and calculations

Dieter Seebach, Tomohiro Yoshinari; Albert K. Beck, Marc-Olivier Ebert; Alejandro Castro-Alvarez, Jaume Vilarrasa