1,3-bis(diarylmethylidene)-2-methylidenecyclohexanes in cycloaddition and cyclodimerization reactions. The role of stereoelectronic factors.
Cycloaddition and cyclodimerization reactions of 1,3-dibenzylidene- and 1,3-bis(p-methoxybenzylidene)-2-methylidenecyclohexanes, i.e., the diaryltrienes with fixed S-cis-configurations of exocyclic double bonds are studied. These compounds undergo in situ cyclodimerization of the [4 + 2]-type upon dehydration of the precursor tertiary alcohols and form endo-adducts in the Diels-Alder reaction with N-phenylmaleimide. In the presence of CF3COOH, acid-catalyzed cyclodimerization takes place leading to methylidene-substituted spirocyclodimers, which undergo intramolecular cyclization upon prolonged contact with CF3COOH to form a fused carbocyclic system containing a central, 'three-petal' fragment of six-membered rings.
Cyclodimerization of the 1-methyl-1,3-diferrocenylallyl cation into 1,3,5-triferrocenyl-4-(1-ferrocenylethenyl)cyclohexene
An unusual cyclodimerization reaction of the 1-methyl-1,3-diferrocenylallyl cation into 1,3,5-triferrocenyl-4-(1-ferrocenylethenyl)cyclohexene has been studied. Two isomeric compounds were isolated and their structures were established as 1,r3,c5-triferrocenyl-4-t-(1-ferrocenylethenyl)cyclohexene and 1,r3, t5-triferrocenyl-4-c-(1-ferrocenylethenyl)cyclohexene on the basis of 1H NMR and 13C NMR spectral data.
Luminescence Phenomena Involving Metal Enolates
1 
Introduction 
 
2 
Metal Enolates 
 
3 
Luminescence of Rare-Earth Enolates 
 
4 
Luminescence Involving s, p and d Metal Block Enolates 
 
5 
Applications 
 
6 
Acknowledgments 
 
 
 
Keywords: 
 
luminescence phenomena involving metal enolates; 
chemistry of metal β-diketonate complexes; 
luminescence of rare-earth enolates; 
photoluminescence of rare-earth β-diketonates; 
diketonate ligand–rare-earth ion energy transfer rates; 
luminescence involving s, p and d metal block enolates; 
photoluminescence of d-transition metal enolates; 
applications - time-resolved detection of luminescence for bioassays