Synthesis and Structures of Cross-Conjugated Bis-dehydroannulenes with a Y-Enediyne Motif and Different π Topologies
✍ Scribed by Arkasish Bandyopadhyay; Babu Varghese; Henning Hopf; Sethuraman Sankararaman
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 200 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
A synthesis of cross‐conjugated bis‐dehydroannulenes with different topologies of the π electrons by Cu^II^‐mediated oxidative coupling of the corresponding terminal acetylenic precursors is reported. In general, of the two possible modes of cyclization, which would yield either a [13]annulene or an [18]annulene, the precursors yielded exclusively the bis‐dehydro[13]annulenes. However, one example of the formation of a bis‐dehydro[18]annulene is also reported. The mode of cyclization to form either the [13]annulene or the [18]annulene is explained on the basis of the conformational preference of the core unit bearing the Y‐enediyne moieties. The structures of the two types of bis‐annulenes have been unequivocally established by means of single‐crystal X‐ray crystallographic analysis.