Synthesis and solid state structure of pyridyl diboroxines linked by a chiral spacer analogous to Tröger’s base

Amine adducts of (4-ClC6H4)3B3O3, Lewis acidity of triarylboroxines, and an XRD study on the related tetraphenylboroxinate(1-) salt, [C6H11NMe3][Ph4B3O3]

“…A few years later, Burg reported the syntheses of 1:1 adducts of ammonia and trimethylamine with trimethylboroxine [2]. In 1958, Snyder et al [3] proposed that the structure of these adducts involved the coordination of the nitrogen atom of the ligand to one of the boron atoms in the boroxine rings ( Figure 1a) and since then there have been several reports of 1:1 adducts of triarylboroxines with N-donor ligands [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Diamine ligands have been reported to bridge between two boroxine acceptors [4] and N-donor ligand / boroxine stoichiometric ratios other than 1 / 1 have also been investigated [4,6,23].…”

Controlling the Assembly of C2-Symmetric Molecular Tectons Using a Thiocarbamate Appended Carbocyclic Cleft Molecule Analogous to Tröger’s Base

“…This gives 1 a predictable V-shape, whose angle (θ) can vary between 83.4° and 104.3° depending on the substitution on the aromatic ring. , The advantages of 1 over Tröger’s base lie in the diol, with the two hydroxyl groups being pointed into the interior of the cleft giving the ability, via hydrogen bonding, to orientate and organize substrates into this uniquely chiral cavity. We have previously emphasized the practicality of 1 by appending the hydroxyl groups with pyridyl functionality, as well as highlighting the self-assembly of these pyridyl adducts with phenylboronic acid to yield bis-boroxine substrates, with the 4-pyridyl analogue being fully characterized by single crystal X-ray analysis emphasizing the chiral space. , …”

A Family of Bisnaphthyl C2-Symmetric and Asymmetric Clefts: Synthesis, Solid-State Structure, and Calculation of the Interplanar Angle

“…Functionalization of the two aromatic rings is important, as it directly affects the cleft angle (θ) and can provide predictability in their positioning. Importantly, the two carbonyl groups at positions C-6 and C-12 of 1 can be stereoselectively reduced, providing anchor points for the introduction of host–guest recognition features. − …”

“…Importantly, the two carbonyl groups at positions C-6 and C-12 of 1 can be stereoselectively reduced, providing anchor points for the introduction of host–guest recognition features. 10 − 16 …”