Substituent Dependent Cyclization Reactions of 1,1'-Bis(alkynyl)ferrocenes with the (C6F5)BH2 . SMe2 Hydroboration Reagent

The reaction of 1,1'-bis(tert-butylethynyl)ferrocene (4 a) with the (C6F5)BH2 . SMe2 reagent results in two-fold hydroboration to give the boron containing [3]ferrocenophane 5. It reacts with xylylisocyanide by insertion into the boron-carbon bond to give the ring enlarged boron containing [4]ferrocenophane derivative 8. 1,1'-Bis(trimethylsilylethynyl)ferrocene (4 b) undergoes the hydroboration reaction with (C6F5)BH2 with inverted regioselectivity. This results in the formation of the 16-membered dimeric bis-boron containing macrocyclic bridged bis-ferrocene system 10.

Automated summary

Two different ferrocene derivatives reacted with hydroboration reagents, resulting in boron-containing cyclic compounds and further formation of dimeric bis-boron containing macrocyclic bridged bis-ferrocene systems with different structures.