1210041-60-3Relevant academic research and scientific papers
The stereodynamics of 1,2-dipropyldiaziridines
Trapp, Oliver,Sahraoui, Laila,Hofstadt, Werner,Koenen, Werner
, p. 284 - 291 (2010)
N-alkylated trans-diaziridines are an intriguing class of compounds with two stereogenic nitrogen atoms which easily interconvert. In the course of our investigations of the nature of the interconversion process via nitrogen inversion or electrocyclic ring opening ring closure, we synthesized and characterized the three constitutionally isomeric diaziridines 1,2-di-n-propyldiaziridine 1, 1-isopropyl-2-n-propyldiaziridine 2, and 1,2-diisopropyldiaziridine 3 to study the influence of the substituents on the interconversion barriers. Enantiomer separation was achieved by enantioselective gas chromatography on the chiral stationary phase Chirasil-β-Dex with high separation factors α (1-isopropyl-2-n-propyldiaziridine: 1.18; 1, 2-diisopropyldiaziridine: 1.24; 100°C 50 kPa He) for the isopropyl substituted diaziridines. These compounds showed pronounced plateau formation between 100 and 150°C, and peak coalescence at elevated temperatures. The enantiomerization barriers ΔG? and activation parameters ΔH? and ΔS? were determined by enantioselective dynamic gas chromatography (DGC) and direct evaluation of the elution profiles using the unified equation implemented in the software DCXplorer. Interestingly, 1-isopropyl-2-n-propyldiaziridine and 1,2-diisopropyldiaziridine exhibit similar high interconversion barriers ?G? (100°C) of 128.3 ± 0.4 kJ mol-1 and 129.8 ± 0.4 kJ mol-1, respectively, which indicates that two sterically demanding substituents do not substantially increase the barrier as expected for a distinct nitrogen inversion process.
Chiral 1,2-dialkenyl diaziridines: Synthesis, enantioselective separation, and nitrogen inversion barriers
Zawatzky, Kerstin,Kamuf, Matthias,Trapp, Oliver
, p. 156 - 162 (2015/03/04)
Trans-1,2-Disubstituted diaziridines form stable enantiomers at ambient conditions because of the two stereogenic pyramidal nitrogen atoms. Functionalized trans-1,2-disubstituted diaziridines can be utilized as a chiral switching moiety between two enantiomeric states in more complex molecular structures. However, the synthesis of functionalized diaziridines is quite challenging, because of the limited tolerance of reaction conditions that can be applied. Here we present a strategy to make trans-1,2-disubstituted diaziridines accessible as versatile building blocks in C-C-bond formations, i.e., the Heck reaction, and therefore introducing aryl substituents. The synthesis of trans-1,2-dialkenyl diaziridines with terminal alkenyl substituents and their stereodynamic properties are described.
