Hexadentate Poly‐Lewis Acids Based on 1,3,5‐Trisilacyclohexane

We report the preparation of hexadentate poly‐Lewis acids (PLA) based on 1,3,5‐trisilacyclohexane backbones bearing two alkynyl groups attached to each of the silicon atoms. A rigid hexadentate PLA bearing six Lewis‐acidic catecholatoboryl‐substituents was prepared by a tin‐boron exchange reaction. Its structure, determined by X‐ray diffraction, is the first of a Lewis‐acid‐functionalised donor‐free trisilacyclohexane. Flexible hexadentate PLA were prepared by hydroboration or hydrosilylation of hexavinyltrisilacyclohexane, resulting in PLA with six 9‐BBN, SiCl 3 , SiCl 2 Me or SiClMe 2 groups. The Lewis‐acidity of the last one was increased by conversion with silver triflate, resulting in a PLA with six highly acidic silyl triflate groups attached to the 1,3,5‐trisilacyclohexane unit as TfOSiMe 2 ‐C 2 H 4 ‐ groups. Host‐guest experiments of the above PLA demonstrated the suitability of the flexible representatives for complexation of neutral Lewis‐based guest molecules under formation of 1 : 6 adducts (host: guest).