Macrocycle Ring Expansion by Double Stevens Rearrangement
作者:Keisha K. Ellis-Holder、Brian P. Peppers、Andrei Yu. Kovalevsky、Steven T. Diver
DOI:10.1021/ol060657a
日期:2006.6.1
New benzimidazolidinone cyclophanes were synthesized through a double Stevens rearrangement employed as a ringexpansion technique. Para-substituted heterophanes underwent efficient rearrangement. Meta-substituted heterophanes were also prepared. Structure analyses of the new cyclophanes are also provided. [reaction: see text]
A New Method for the Synthesis of Imidazolidinone- and Benzimidazolone-Containing [2.2]Cyclophanes
作者:Keisha K. Ellis、Burkhardt Wilke、Yuegang Zhang、Steven T. Diver
DOI:10.1021/ol0064866
日期:2000.11.1
nucleophilic addition of bisthiols to heterocyclic bisacetals gives sulfur-containing macrocycles in good yield. Crossover experiments revealed that the acid-catalyzed N-acyl iminium cyclization for the imidazolidinones is reversible. The sulfur atom in the bridge was extruded photochemically, giving new [2.2]heterophanes containing the imidazolidinone and benzimidazolone ring systems. The determined crystal