ja7b03986_si_001.pdf (20.65 MB)
Uncatalyzed Carboboration of Seven-Membered-Ring trans-Alkenes: Formation of Air-Stable Trialkylboranes
journal contribution
posted on 2017-06-01, 00:00 authored by Jillian
R. Sanzone, Chunhua T. Hu, K. A. WoerpelSeven-membered-ring trans-alkenes undergo rapid,
uncatalyzed carboboration reactions to form trialkylboranes as single
diastereomers. In contrast with other trialkylboranes, which can ignite
in the presence of oxygen, these trialkylboranes are stable in air.
Hindered trialkylboranes can undergo reverse hydroboration reactions
to form allylic silanes or can be oxidized to afford highly substituted
triols. This reaction sequence permits the construction of compounds
with up to five consecutive stereocenters. Control experiments and
computational studies support a concerted mechanism for the migratory
insertion of the alkene into the carbon–boron bond, similar
to the mechanism for hydroboration.