Gassman-Fentiman tool

The nature of electronic effects in cationic reactions has been probed by application of the Gassman-Fentiman tool of increasing electron demand.67 Aryl-substituted cationic centers can be made more electron demanding (i.e., electrophilic) by introduction of electron-withdrawing substituents into the aryl ring. 

Famum and Olah s groups have extended the so-called Gassman-Fentiman tool of increasing electron demand coupled with H and NMR spectroscopy as the structural probe under stable ion conditions to show the onset of... 

Gassman, P.G. Fentiman Jr., A.F. J. Am. Chem. Soc., 1969, 91, 1545 1970, 92, 2549. For a discussion of the use of the tool of increasing electron demand to probe neighboring-group activity by double bonds, sigma bonds, and aryl rings, see Lambert, J.B. Mark,... 

Gassman and Fentiman proposed the so-called tool of increasing electron demand of the developing cation centre For their example of the solvolysis of 7-syn-aryl-7-anti-norbomenyl-p-nitroteizoates they confirmed the -participation by three criteria ... 

---