¹³C NMR study of N‐unsubstituted aziridines: I—steric effects, pseudoconjugation

Abstract

Abstract--13C chemical shifts for twenty-nine alkyl and phenyl substituted N-unsubstituted aziridines have been measured. Additivity parameters for methyl, phenyl and aziridyl carbons have been derived with the aim of testing the consistency of the assignments made on the basis of chemical shift considerations and off-resonance decoupling information. The observed chemical shifts are discussed in terms of steric and pseudoconjugation effects.

A Density Functional Study of the 13C NMR Chemical Shifts in Functionalized Single-Walled Carbon Nanotubes

“…Upon the second functionalization, the shifts of the sp 3 carbons also increase by 9.4 and 4.4 ppm for the (8,0) and (9,0) SWNTs, respectively. They are comparable to shifts of 54.9 and 47.9 ppm for aziridine trisubstituted with methyl, phenyl, and ethyl or two phenyl and one isopropyl group . Thus, the variations found here for the shifts of the substituted SWNT carbons are in line with variations of the 13 C shifts of aziridine derivatives containing aromatic groups.…”

“…Interestingly, this shift is rather independent of the nanotube diameter, varying by less than 3 ppm. It is comparable to a shift of 43.7 ppm for 2,3- trans -diphenylaziridine and of a 43.8 ppm shift for aziridine trisubstituted with methyl and two phenyl groups trans to each other …”

An Improved and Mild Wenker Synthesis of Aziridines

“…7 The analytical data of all known aziridines are identical to those data previously reported in the literature. [17][18][19][20][21][22][23][24][25] Aliphatic Amino Alcohol Hydrogen Sulfates 2; General Procedure A 150-mL, two-necked, round-bottom flask was fitted with a magnetic stirrer bar and an addition funnel. The flask was charged with a vicinal amino alcohol (10 mmol) and Et 2 O (100 mL).…”

Observations on the Modified Wenker Synthesis of Aziridines and the Development of a Biphasic System

“…All infrared thin film spectra were acquired using sodium chloride plates. All 1 H and 13 C NMR spectra were measured at 400.13 and 100.62 MHz. The solvent used for NMR spectroscopy was CDCl 3 (unless stated otherwise) using TMS (tetramethylsilane) as the internal reference.…”

“…2-Phenylaziridine 8. 13 Colorless oil (0.51 g, 80%); 1 H NMR (400 MHz, CDCl 3 ) 1.83 (d, J = 3.2 Hz, 1H), 2.24 (d, J = 6.0 Hz, 1H), 3.04−3.06 (m, 1H), 7.25−7.36 (m, 5H) ppm; 13 The One-Pot Protocol. N-Benzylethanolamine (15.2 g, 100 mmol) was dissolved in toluene (300 mL), and the reaction mixture was cooled to 0 °C followed by the dropwise addition of chlorosulfonic acid (11.7 g, 6.6 mL, 100 mmol).…”