Ring strain in boroxine rings: computational and experimental considerations

Beckmann, Jens; Dakternieks, Dainis; Duthie, Andrew; Lim, Allan Ε. Κ.; Tiekink, Edward R. T.

doi:10.1016/s0022-328x(01)01060-9

Cited by 69 publications

(57 citation statements)

References 44 publications

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“…The basic features of the structure of 1 is quite similar to those of previously reported R 3 B 3 O 3 ÁL compounds, where L is a simple Lewis donor, and many of which e.g. Ph 3 B 3 O 3 Ápy[12], (4-MeC 6 H 4 ) 3 B 3 O 3 Á(4-picoline) Reagents and conditions: (i) 1 eq. 4,4 0 -bpy, benzene, 65°C; (ii) eq.…”

supporting

confidence: 77%

New Adducts of Triphenylboroxine and Bis-pyridines: Syntheses and Crystal Structures of (Ph3B3O3)(η 1-4,4′-bpy), (Ph3B3O3)2(μ-4,4′-bpy) and (Ph3B3O3)2(μ-bpe)

et al. 2015

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The treatment of phenylboronic acid PhB(OH) 2 with 4,4 0 -bipyridine (4,4 0 -bpy) in a 3:1 ratio afforded adduct [(Ph 3 B 3 O 3 )(g 1 -4,4 0 -bpy)] (1), whereas the reaction of PhB(OH) 2 with 4,4 0 -bpy in a 6:1 ratio afforded adduct [(Ph 3 B 3 O 3 ) 2 (l-4,4 0 -bpy)] (2). Similarly, the reaction of PhB(OH) 2 with trans-1,2-bis(4-pyridyl)ethylene (bpe) in a 6:1 ratio gave bpe bridged adduct [(Ph 3 B 3 O 3 ) 2 (l-bpe)] (3). The crystal structures of 1ÁC 6 H 6 , 2Á2C 7 H 8 , 2ÁC 6 H 14 , and 3ÁC 6 H 6 , along with other spectroscopic properties are reported. The weak NÁÁÁH-C hydrogen-bonds exist in the one-dimensional chains of 1ÁC 6 H 6 . Graphical Abstract Treatment of PhB(OH) 2 with 4,4 0 -bpy or bpe under different conditions afforded three new adducts [(Ph 3 B 3 O 3 )(g 1 -4,4 0 -bpy)] (1), [(Ph 3 B 3 O 3 ) 2 (l-4,4 0 -bpy)] (2) and [(Ph 3 B 3 O 3 ) 2 (l-bpe)] (3) through the B-N dative bonds.

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supporting

confidence: 77%

New Adducts of Triphenylboroxine and Bis-pyridines: Syntheses and Crystal Structures of (Ph3B3O3)(η 1-4,4′-bpy), (Ph3B3O3)2(μ-4,4′-bpy) and (Ph3B3O3)2(μ-bpe)

et al. 2015

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“…The sum of the internal angles of the B 3 O 3 ring is 714.29 • indicating a nonplanar ring system (sum 720 • ). In contrast, in the structure of (PhBO) 3 ·pyridine, the B 3 O 3 ring is nearly planar with a sum of the angles of 719.0 • [25]. This shows that the conformation at theB(1) atom in 1 is more distorted when compared with that of (PhBO) 3 ·pyridine.…”

Section: Resultsmentioning

confidence: 88%

N-Heterocyclic Carbene-facilated Condensation of 3-Methylphenylboronic Acid to the Boroxine

Zhang

Dong

et al. 2013

Zeitschrift Für Naturforschung B

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The adduct of (3-MeC 6 H 4 ) 3 B 3 O 3 with an N-heterocyclic carbene (NHC = 1,3-diethyl-4,5-dimethylimidazol-2-ylidene) was prepared by reacting 2.5 equiv. of 3-methylphenylboronic acid with 1 equiv. of the NHC. This reaction shows a novel carbene-facilitated condensation of substituted phenylboronic acid monomers. The structure of the compound (3-MeC 6 H 4 ) 3 B 3 O 3 (NHC) (1) has been characterized by 1 H NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction studies.

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“…4 10 -30 esu, noting however that the method of calculation is not the same 46 . As it can be observed, experimental or computed β values of a boroxine derivative like A5…”

Section: -Results and Discussionmentioning

confidence: 99%

“…Boroxine ring The boroxine core is stable, planar 26,45 in both DFT optimized and crystallographic structures, electron-deficient, and has a low aromaticity 46 .…”

Section: Systems Under Considerationmentioning

confidence: 99%