Structural Constraint of Overcrowded Alkenes: Macrocyclization of 9,9′-Bifluorenylidene
We report the successful synthesis of Cyclic BF and Cyclic Bis-BF, in which alkyl bridges installed at the 2-position serve as precise structural handles for constructing macrocyclic architectures with fine-tuned molecular strain. Enabled by a modified Barton–Kellogg reaction, this strategy overcomes the significant...