Atypical “Masked” Frustrated Lewis Pair Character in a Geminal‐Linked Phosphine‐Borane

Abstract

We report the synthesis and reactivity of the geminal‐linked fluorene‐derived P/B frustrated Lewis pair (FLP) iPr2P(C13H8)BCy2 (1). Compound 1 displays anomalous behavior towards small molecules, acting as a “masked” FLP. This behavior stems from significant polarization of the B−C(fluorene) bond in 1, as identified by density functional theory (DFT) computations. We exploit this B−C bond polarity through reactions with PhPCl2, H3N ⋅ BH3, and iPrNH2, demonstrating P−Cl and N−H bond activation, respectively.

Frustrated Lewis pair adducts of alkynyl-capped tetrelenes

“…While the silylene congener PB{Si(CCSiMe 3 ) 2 } ( 3 ) remained intact after heating to 150 °C and exposure to light, the germanium analogue PB{Ge(CCSiMe 3 ) 2 } ( 4 ) rearranged upon heating to give a multicyclic activation product that featured an unusually weak intramolecular Ge( ii )-alkyne interaction. 19 Future work will involve modifying the FLP chelate 20 to encourage the selective formation of unsaturated polytetrelanes of the general form [E(CCR) 2 ] n , for their eventual use as conducting inorganic polymers and precursors to carbide ceramics ( e.g. SiC and GeC).…”