Ferrocenes in Frustrated Lewis Pair Chemistry

Abstract

Frustrated Lewis pairs (FLPs) composed of bulky Lewis acids and bases do not quench each other efficiently by adduct formation. They can react jointly, for example in small molecule activation. A series of FLPs and typical FLP reactions at ferrocene‐derived frameworks are presented. This involved ferrocene‐bonded nitrogen or phosphorus bases in conjunction with strongly electrophilic pentafluorophenyl containing boron Lewis acids. Reactions of these ferrocene‐derived FLPs include activation of dihydrogen under mild conditions and catalytic hydrogenation reactions but also FLP reactions with alkenes or alkynes.

Indirect “No-Bond” 31P···31P Spin–Spin Couplings in P,P-[3]Ferrocenophanes: Insights from Solid-State NMR Spectroscopy and DFT Calculations

“…To probe the structural potential of these parameters, we report here the results of a detailed solid-state NMR spectroscopic investigation of 31 P– 31 P no-bond spin–spin couplings in P , P -[3]­ferrocenophane-based bisphosphanes ( 1 – 5 ). These systems are of great interest, since they represent a class of bidentate ligands used in coordination chemistry, , in copolymerization processes , and in FLP chemistry. , By using different types of substituents at phosphorus (e.g., phenyl, cyclohexyl or iso-propyl groups), the phosphorus–phosphorus distances can be varied over a rather wide range: the shortest distance of 3.49 Å is observed for ( S , S , S pl )- 3 , while the largest one is 4.06 Å for the ( S , S , S pl ) enantiomer of 4 . Of course, such distance variations also alter the chemical properties of these compounds regarding their coordination behavior, since larger cone angles describing the steric bulkiness arise in case of larger phosphorus–phosphorus separations (see Table ).…”