Facile Synthesis of Cyclic Polyphenylenes by Consecutive Inter- and Intramolecular Cycloadditions of ortho-, meta-, and para-Phenylene-Tethered Triynes

Consecutive inter- and intramolecular [2+2+2] cycloadditions of various phenylene-tethered triynes were comprehensively studied by using chiral rhodium catalysts. ortho -Phenylene-tethered triynes gave chiral o , o , o , o -tetraphenylenes in high-to-excellent enantiomeric excess as dimers. meta -Phenylene-tethered triynes gave chiral o , m , o , m -tetraphenylenes in moderate enantiomeric excess as dimers along with hexaphenylenes as trimers. This is the first synthesis of cis - o , m , o , m -tetraphenylenes; one structure was ascertained by X-ray crystal structure analysis. para -Phenylene-tethered triynes gave o , p , o , p , o , p -hexaphenylenes as trimers along with the formation of o , p , o , p , o , p , o , p -octaphenylenes as tetramers. 1 Introduction 2 Results and Discussion 2.1 ortho -Phenylene-Tethered Triynes 2.2 Naphthylene-Tethered Triynes 2.3 meta -Phenylene-Tethered Triynes 2.4 para -Phenylene-Tethered Triynes 3 Conclusion