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Updated: Feb 26, 2026

Synthesis of 1,2-Azaborines and the Preparation of Their Protein Complexes with T4 Lysozyme Mutants
Published on: March 25, 2017
Generation of 1,2-azaboretidines via reduction of ADC borane adducts
H Braunschweig1, A Gackstatter1, T Kupfer1
1Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany . Email: h.braunschweig@uni-wuerzburg.de ; http://www-anorganik.chemie.uni-wuerzburg.de/Braunschweig/.
Abstract:
Reaction of the acyclic (diamino)carbene (ADC) :C(NiPr2)2 (1) with different dihaloboranes of the type RBX2 (R = Mes, Dur; X = Cl, Br) smoothly afforded a novel class of ADC-stabilized borane adducts. For MesBBr2 however, the reaction did not stop at the adduct level, but an uncommon rearrangement process occurred, which eventually resulted in the formation of a 5-membered boracycle after elimination of mesitylene. Chemical reduction of the ADC borane adducts by KC8 selectively yielded air stable 1,2-azaboretidines. Detailed DFT studies suggest a reduction mechanism involving a highly reactive borylene intermediate, which is converted into the boracycles via a rearrangement/C-H activation sequence.
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