Dipole-stabilized carbanions: a computational study of N-methylformamide anion and methyl N-methylcarbamate anion.
The relative energies of the rotamers of the carbanions derived from N-methylformamide and methyl N-methylcarbamate have been studied at the MP2/6-311+G and B3LYP/6-311+G theoretical levels. There results are in good agreement but differ substantially from previously reported HF/6-31G calculations for the N-methylformamide anions. Transition states for rotation and inversion of the anions were located. The methoxy group in methyl N-methylcarbamate has a large effect on the relative energies of the anions. The results are compared with those previously reported for the N-(methoxycarbonyl)piperidine anions, and it is found that the decreased conformational flexibility has an effect on the relative energies of these ions.
Wiberg
Kenneth B
KB
Department of Chemistry, The University of Connecticut, Storrs, Connecticut 06269-3060, USA. kenneth.wiberg@yale.edu
Bailey
William F
WF
D000838:Anions / Q000737:chemistry*; D002219:Carbamates / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005559:Formamides / Q000737:chemistry*; D008962:Models, Theoretical; D008968:Molecular Conformation
D000838:Anions; D002219:Carbamates; D005559:Formamides; C020401:N-methylcarbamate; C002950:methylformamide