116230-22-9Relevant academic research and scientific papers
Stereochemistry of β-deuterium isotope effects on amine basicity
Perrin, Charles L.,Ohta, Brian K.,Kuperman, Joshua,Liberman, Jordan,Erdelyi, Mate
, p. 9641 - 9647 (2005)
Secondary β-deuterium isotope effects on amine basicities are measured using a remarkably precise NMR titration method. Deuteration is found to increase the basicity of methylamine, dimethylamine, benzylamine, N,N-dimethylaniline, 2-methyl-2-azanorbornane, and pyrrolizidine. The increase in dimethylamine arises entirely from enthalpy, contrary to a previous report. The method permits a determination of intramolecular isotope effects in 1-benzyl-4-methylpiperidine and 2-benzyl-2-azanorbornane. It is found that deuteration has a larger isotope effect when either antiperiplanar or synperiplanar to a lone pair, but the synperiplanar effect is smaller, as confirmed by computations. The isotope effect is attributed to a lowered zero-point energy of a C-H bond adjacent to an amine nitrogen, arising from delocalization of either a syn or an anti lone pair, and with no detectable angle-independent inductive effect.
Meisenheimer and other rearrangements of N-oxides derived from 2-azabicyclo[2.2.1]hept-5-enes; the influence of reaction conditions and stereochemistry at nitrogen
Malpass, John R.,Skerry, Paul S.,Rimmington, Stuart L.
, p. 679 - 691 (2007/10/03)
N-Benzyl-2-azabicyclo[2.2.1]hept-5-ene reacts rapidly with m-CPBA and, on basification, a single N-oxide is released which rapidly forms N-benzyl-2-oxa-3-azabicyclo[3.2.1]oct-6-ene via a Meisenheimer rearrangement at room temperature. In addition, competi
