44697-AC1
Generation, Study, and Application of Dicationic Intermediates
Title: Generation, Study, and Application of Dicationic Intermediates
PI: KLUMPP, DOUGLAS A
Date: 09/01/2006 to 08/31/2008
Institution: Northern Illinois University
Progress Report
As a result of this PRF funding, we have published 7 manuscripts.1-7 We also have one other manuscript that has been submitted and we have additional data that will contribute to 6 other manuscripts. Moreover based on the experiments from this grant, 8 student research-presentations have been given at international or regional chemistry meetings.
Published or submitted manuscripts acknowledging this grant
We recently submitted a manuscript as a communication to the Journal of the American Chemical Society, entitled "N-Heterocyclic Superelectrophiles and Evidence for Single Electron Transfer (SET) Chemistry." It was shown that the superelectrophilic oxazole derivative undergoes a dimerization reaction when it is generated in the presence of ferrocene. This represents the first example of SET chemistry involving a superelectrophile.
In recently published work (Journal of Organic Chemistry, title: "Preparation of Aza-Polycyclic Aromatic Compounds via Superelectrophilic Cyclizations."), we reported that the superacid-catalyzed cyclization of olefins to aza-polycyclic aromatic compounds is extremely efficient1 and it represents an improvement of an earlier reported synthetic route employing alcohol substrates.8
Another publication citing this PRF grant is a paper entitled, "Superelectrophiles: Charge-Charge Repulsive Effects," which was published recently to Chemistry: A European Journal, as a review article describing our work.2
In other work, we have studied the acid-catalyzed chemistry of quinones.3 Both experimental and theoretical results have suggested the formation of reactive diprotonated electrophiles in solution (eq 5).
Among the papers from 2008 citing the PRF grant, a manuscript entitled "Superacid-Promoted Reactions of a-Ketoamides and Related Systems" was published in the Journal of Organic Chemistry. In this paper, we describe the superacid-promoted condensations of a-ketoamides to give oxyindole products.4
During our study of N-acyliminium ion chemistry, we found examples of a cyclization reaction remarkably similar to the Nazarov reaction.5 We have found that superacid-catalyzed reactions can lead to a new variation of the Nazarov reaction. In other N-acyliminium ion investigations, we have found strong evidence for the involvement of dicationic, superelectrophiles.6
We have also studied the Knorr cyclization, a reaction used to prepare several commercial pharmaceuticals having the quinolin-2-one structure.7 Most heterocyclic reference books and reviews suggest that the Knorr reaction occurs through an N,O-diprotonated intermediate. Using theoretical calculations and spectroscopic methods, we show that the O,O-diprotonated intermediate is the actual intermediate in this reaction. Synthetic studies were also done to show that CF3SO3H is an outstanding catalyst for the reaction.7
On-going projects supported by this grant
We have several projects that are nearing completion and will cite this PRF grant upon publication. One such research study was done in an advanced organic chemistry teaching laboratory at Northern Illinois University. As an example of the conversions from this study, the condensations to the triarylmethane and the aza-polycyclic aromatic compound were accomplished.
We are also very near to the submission of a manuscript describing our superacid-promoted conversions leading to polycyclic aromatic hydrocarbons (PAHs). We have found that our cyclization-benzene elimination chemistry can be effective in providing PAHs and substituted derivatives.
Literature Citations
(1) (2) (3) (4) (5) (6) (7) (8)
