Potential Amino Derivatives of Isoindole

Ultraviolet spectral comparisons indicate that structure 107 predominates over 108 when R = H or OH, but that 107 is the predominant form when R = aryl. - Similarly, 109 predominates over 110 by a large factor when R = H, OH, or Me, and by a smaller factor when R is a higher alkyl group, but 110 predominates when R is an aryl group. (For a discussion of guanidine derivatives corresponding to 110, see reference 110.) 

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There is little information on simple 3-aminoindoles (69BSF2004), but the 3-p-toluenesul-phonamido compounds are certainly amino rather than imino compounds (73JOC11, 72JCS(Pl)241l). The scant data on potential amino derivatives of isoindole are somewhat contradictory (B-76MI30406). The IR spectra of the indolizines (81 R = H) (in CHCI3) and (81 R = COMe) (solid state) show that they exist in amino forms (65JCS2948). 

In light of the improved host properties we found for modified CD, we investigated the potential effects of HP- -CD on a wide array of amino acid OPA-derived isoindoles, to see if significant fluorescence enhancements could be observed, and in addition, whether a stabilization of the isoindoles could be obtained (this was not observed in the above-mentioned previous studies) [99]. Our measurements showed modest fluorescence enhancements for some of the derivatives, including lysine and glycine, with values between 2 and 3. However,... 

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