𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Structural studies by 1H and 13C dynamic n.m.r.: Part III alternative protonation sites in carbonyl conjugated enamines of the type R1C(O)CHCHNR2R3

✍ Scribed by Lech Kozerski

Publisher
John Wiley and Sons
Year
1977
Tongue
English
Weight
510 KB
Volume
9
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

^13^C magnetic resonance spectra of several enamino ketones with secondary and tertiary amino groups were obtained for trifluoroacetic acid solutions. In both series O‐protonation is predominant and the chemical shifts are related to the electron density changes with respect to the parent base. The spectra of the tertiary compounds are interpreted in terms of slow rotation around the C–1C–2 and C–3N bonds discernible at room temperature. O‐protonated forms of the secondary enamino ketones undergo further reaction on C–2 yielding pyridinium salts. The mechanism of formation of the quaternary salts is interpreted and the additivity parameters of the ^13^C n.m.r. chemical shifts in the pyridinium ions is briefly discussed.

📜 SIMILAR VOLUMES

N.m.r. studies in the heterocyclic serie
N.m.r. studies in the heterocyclic series: XVI—determination of the structure of 3-azidoindazole by 1H and 13C n.m.r. spectroscopy
✍ Alain Fruchier; Ermitas Alcalde; José Elguero 📂 Article 📅 1977 🏛 John Wiley and Sons 🌐 English ⚖ 155 KB 👁 1 views

## Abstract The 1‐NH structure for 3‐azidoindazole has been demonstrated by the observation of ^1^H^1^H and ^13^C^1^H couplings involving the hydrogen atom attached to nitrogen. A comparison between 3‐azidoindazole and indazole shows that both compounds have the same tautomeric structure.

Structural studies by 1H and 13C d.n.m.r
Structural studies by 1H and 13C d.n.m.r.: I—barrier to trans-cis isomerization in aliphatic enamino ketones of the type RCOCHCHNHR1
✍ E. Czerwińska; Lech Kozerski; J. Boksa 📂 Article 📅 1976 🏛 John Wiley and Sons 🌐 English ⚖ 557 KB

## Abstract D.n.m.r. studies have been performed involving the measurement of rates of __trans__‐__cis__ isomerization of aliphatic enamino ketones of the type RCOCHCHNHR~1~, by means of equilibration experiments and the method of finding the coalescence temperature. Simultaneous observation of