作者:Herman Zagppey、Roel H. Fokkens、Steen Ingemann、Nico M. M. Nibbering、Helena Florencio
DOI:10.1002/oms.1210260610
日期:1991.6
AbstractThe regioselectivity of methyl cation transfer from (CH3)2F+, (CH3)2Cl+ and (CH3)3O+ to 1‐phenyl‐2‐aminopropane was studied by Fourier transform ion cyclotron resonance in combination with collision‐induced dissociation and neutralization‐reionization mass spectrometry of the stable [M + CH3]+ ions formed in a chemical ionization source. The (CH3)2F+ ion transfers a methyl cation to the NH2 group and the phenyl ring with almost equal probability. Predominant CH3+ transfer to the NH2 group is observed for the (CH3)2Cl+ ion whereas the (CH3)3O+ ion reacts almost exclusively at the amino group. The preference for methylation at NH2 is discussed in terms of a lower methyl cation affinity of the phenyl ring than of the amino group and the existence of an energy barrier for methylation of the phenyl moiety.