A series of octa-R-substituted bromo-s-hydrindacenes, “Rind-Br,” have been synthesized by a sequence of the Lewis acid catalyzed intramolecular Friedel–Crafts reaction, bromination and vice versa. Their structural features and physical properties depend on the eight R-substituents at the four benzylic positions on the s-hydrindacenyl skeleton. The molecular structures of the Rind-Br have been confirmed by X-ray crystallography, indicating the unique structural diversities of the bulky Rind groups.
Formation of Active Cyclic Five‐membered Frustrated Phosphane/Borane Lewis Pairs and their Cycloaddition Reactions
作者:Shunxi Dong、Constantin G. Daniliuc、Gerald Kehr、Gerhard Erker
DOI:10.1002/chem.201904919
日期:2020.1.13
The cyclic five-membered frustrated phosphane/borane Lewis pairs 11 a, b featuring the bulky octaethylhydrindacenyl- (Eind) substituent or its mono-bromo derivative (Br Eind) at phosphorus are monomeric at room temperature. The reactive frustrated Lewis pairs (FLPs) cleave dihydrogen. The cyclic FLP 11 b (Br Eind) undergoes 1,2-P/B addition to ethylene to give the zwitterionic heteronorbornane derivative 14 b