A free boratriptycene-type Lewis superacid

Abstract

Bicyclic pyrazabole-bridged ferrocenes with BH groups at their bridgehead positions were prepared from [Li(thf)]2[1,1’-fc(BH3)2] and pyrazole or 3,5-dimethylpyrazole in the presence of Me3SiCl (1 or 1Me, respectively; 1,1’-fc = ferrocenylene);...

Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study

“…The B–P bond distance in B­(C 6 H 4 ) 3 CH·PPh 3 (1.976(4) Å) is the shortest among known complexes with phosphines bearing aromatic substituents. More recently, cationic pyramidal LA based on the pyrazabole-bridged ansa-ferrocene was reported by Henkelmann et al in 2022 . Sulfur-containing cationic derivatives of 9-boratriptycene (Scheme c) were experimentally realized by the Berionni group .…”

“…More recently, cationic pyramidal LA based on the pyrazabole-bridged ansa-ferrocene was reported by Henkelmann et al in 2022. 27 Sulfur-containing cationic derivatives of 9-boratriptycene ( Scheme 1 c) were experimentally realized by the Berionni group. 28 Formal replacement of the CH group in the aromatic ring of B(C 6 H 4 ) 3 CH by the nitrogen atom results in 1-aza-9-boratriptycene, which may be considered an intramolecular FLP.…”

Are Ar3SbCl2 Species Lewis Acidic? Exploration of the Concept and Pnictogen Bond Catalysis Using a Geometrically Constrained Example

“…In the context of Lewis acid chemistry, it has long been known that simply incorporating silicon into a rigid five-membered structure elevates its Lewis acidity . Similar strategies have been employed in the chemistry of group 13 compounds as in the case of distorted or pyramidalyzed boranes, with externally exposed “vacant” oribtals . The same concepts have driven a surge of efforts in pnictogen chemistry, where ligand-imposed geometrical constraints have been used to adjust not only the Lewis acidity of the main group element but also its redox reactivity .…”

In situ pyrazolylborate ligand synthesis and coordination behaviours in aluminum oxo clusters

“…[1][2][3] These include phenylboronic acid derivatives, boronenes, diborenes, diborynes, and boron-containing heterocycles with potential applications in the biomedical field and light-harvesting fluorescent dyes. 4,5 Boron-centered ligands form metal complexes through multiple binding modes, which endow the resulting complexes with unique and unexpected properties. In inorganic chemistry, the planar [BO 3 ] 3− anionic group is the most suitable basic structural unit of nonlinear optical crystals for ultraviolet and deep-UV light generation.…”