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.
Department of Chemistry, The University of Connecticut, Storrs, Connecticut 06269-3060, USA. kenneth.wiberg@yale.edu
Kenneth B
KB
Wiberg
William F
WF
Bailey
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