Do deprotonated amidoximes undergo the Tiemann rearrangement in the gas phase?
Abstract
The Tiemann rearrangement in the condensed phase involves base-catalysed transformation of suitably substituted amidoximes to ureas, e.g. R1(NH2)CNOR2 [graphic omitted] NHCNR1 [graphic omitted] R1NHCONH2
In contrast, deprotonated amidoximes, in the gas phase, undergo only minor reaction through Tiemann intermediates. Instead, they decompose by loss of hydroxylamine, e.g.–NHC(Me)NOH ↔ NHC(Me)– [graphic omitted]OH →[(MeCN)–NHOH]→–CH2CN + NH2OH a process substantiated by 15N and 2H labelling and product-ion studies.