Chemical Reactions in the Axle of Rotaxanes – Steric Hindrance by the Wheel

✍ Scribed by Amir Hossain Parham; Björna Windisch; Fritz Vögtle

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 299 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199905)1999:5<1233::aid-ejoc1233>3.0.co;2-q

✦ Synopsis

Electrophilic additions / Bromine addition to double bonds / Hydrogenation of double bonds / Rotaxanes / Supramolecular chemistry Here we report on the possibility of using rotaxane wheels free axle compounds 6a and 6b, indicating steric hindrance of the C=C double bond by the wheel of the rotaxane in each as noncovalent protecting groups which significantly decrease the activity of functional groups in the central part case. Nontheless, the rotaxane 9 with an aliphatic (succinic acid) middle region in its axle can be prepared in this of the axle. The amide-linked rotaxanes 5a and 5b, each containing a C=C double bond in their axle, have been manner. Dehydrobromination of the axle in the rotaxane 15 yields the rotaxane 16 with a CϵC triple bond located in the synthesised. The catalytic hydrogenation of these two rotaxanes proceeds slower than those of the corresponding centre of the axle.

[a] Kekule ´-Institut für Organische Chemie und Biochemie der Unianes, [14] the incorporation of double bonds into the axle of versität Bonn, neutral amide-linked rotaxanes described in this paper for