Ion Association Assisted Lithium Ion “Claw”

N-Methoxycarbonyl-1H-azepine-2,7-dicarboxaldehyde (I) was synthesized via the SeO2-mediated oxidation of N-methoxycarbonyl-2,7-dimethyl-1H-azepine. The reductions of I in tetrahydrofuran with 6Li or 7Li resulted in anion radicals, which are tightly associated with the lithium cations. EPR and ab ini...

Full description

Saved in:
Bibliographic Details
Published in:Journal of organic chemistry 1999-03, Vol.64 (6), p.1849-1852
Main Authors: Schertz, Tyler, Lash, Timothy D, Petryka, Joseph C, Reiter, Richard C, Stevenson, Cheryl D
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:N-Methoxycarbonyl-1H-azepine-2,7-dicarboxaldehyde (I) was synthesized via the SeO2-mediated oxidation of N-methoxycarbonyl-2,7-dimethyl-1H-azepine. The reductions of I in tetrahydrofuran with 6Li or 7Li resulted in anion radicals, which are tightly associated with the lithium cations. EPR and ab initio calculations both show a nonequivalency in all of the protons in I -•,Li+ due to the closer approach of the Li+ to one of the carbonyls and a twist of the ester carbonyl group (slow rotation of the carbamate group) toward the Li+. Further, as predicted by the MO calculations, I -•,Li+ appears to exist with the nitrogen puckered above the twisted ring system, and the lithium cation is asymmetrically complexed between the two electronegative aldehydic oxygen atoms and the carbamate carbonyl oxygen. It is also Coulombically attracted to the puckered and twisted ring system.
ISSN:0022-3263
1520-6904
DOI:10.1021/jo981672z