Chemoselective boron-carbon bond cleavage by hydroboration of borirenes.
We report on the hydroboration of 1-[bis(trimethylsilyl)amino]-2,3-diethylborirene (3) with 9-borabicyclo[3.3.1]nonane (9-BBN), which led through ring-opening to an amino(vinyl)borane. The viscous borane was subsequently converted into a crystalline borate on treatment with MeLi. Both compounds were fully characterized by multinuclear NMR spectroscopy and in case of the latter by single-crystal X-ray diffraction analysis. To elucidate the reaction mechanism of the unexpected boron-carbon bond cleavage, DFT calculations of energy minima and transition states for the hydroboration were carried out.
Braunschweig
Holger
H
Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. h.braunschweig@mail.uni-wuerzburg.de
Herbst
Thomas
T
Radacki
Krzysztof
K
Frenking
Gernot
G
Celik
Mehmet Ali
MA