Double Naphthalene‐Tagged Cyclodextrin‐Peptide Capable of Exhibiting Guest‐Induced Naphthalene Excimer Fluorescence

A cyclodextrin‐peptide hybrid (17NNβ) bearing two naphthalene units in the peptide side chain has been designed and synthesized as a novel chemosensor molecule. Circular dichroism study of the compound revealed that the peptide has α‐helix structure with a helix content of 41%. The peptide revealed both monomer and excimer emission and the intensity of the excimer emission increased while that of the monomer emission decreased upon addition of the guest compound. This behavior was observed for various guest molecules, suggesting that the system can be used for detecting molecules in aqueous solution.     

Reductive dimerization and reduction of imines using lanthanum metal

The treatment of N‐benzylideneaniline ( 1a ) with a half‐equivalent of lanthanum metal and a catalytic amount of iodine gave the reductive dimerization product of 1a , a vic‐diamine, in good yield. Various vic‐diamines were synthesized from aldimines in this manner in moderate to good yields. Our findings suggest that electrons of a zero‐valent lanthanum metal were efficiently utilized in this reductive dimerization. In the reaction of ketimines, however, a similar reductive dimerization did not take place, and the corresponding amines were formed as the sole products. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:131–135, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10007