156836-00-9Relevant academic research and scientific papers
Spectroscopic and computational investigations of the thermodynamics of boronate ester and diazaborole self-assembly
Goldberg, Alexander R.,Northrop, Brian H.
, p. 969 - 980 (2016/02/18)
The solution phase self-assembly of boronate esters, diazaboroles, oxathiaboroles, and dithiaboroles from the condensation of arylboronic acids with aromatic diol, diamine, hydroxythiol, and dithiol compounds in chloroform has been investigated by 1H NMR spectroscopy and computational methods. Six arylboronic acids were included in the investigations with each boronic acid varying in the substituent at its 4-position. Both computational and experimental results show that the para-substituent of the arylboronic acid does not significantly influence the favorability of forming a condensation product with a given organic donor. The type of donor, however, greatly influences the favorability of self-assembly. 1H NMR spectroscopy indicates that condensation reactions between arylboronic acids and catechol to give boronate esters are the most favored thermodynamically, followed by diazaborole formation. Computational investigations support this conclusion. Neither oxathiaboroles nor dithiaboroles form spontaneously at equilibrium in chloroform at room temperature. Computational results suggest that the effect of borylation on the frontier orbitals of each donor helps to explain differences in the favorability of their condensation reactions with arylboronic acids. The results can inform the use of boronic acids as they are increasingly utilized in the dynamic self-assembly of organic materials and as components in dynamic combinatorial libraries.
Pronounced effects of substituents on the iridium-catalyzed borylation of aryl C-H bonds
Liskey, Carl W.,Wei, Carolyn S.,Pahls, Dale R.,Hartwig, John F.
, p. 5603 - 5605 (2010/01/31)
Iridium trisboryl complexes containing bisphosphine and bipyridine ligands and pinacolate and catecholate substituents on boron are reported. A large difference in reactivity towards the borylation of C-H bonds is observed for this series of trisboryl complexes, and this difference is attributed to the electron-donating properties of the pinacolate vs. catecholate groups, and the steric and electronic properties of bipyridine vs. bisphosphine ligands.
