Trans-diborylation of alkynes: pseudo-intramolecular strategy utilizing a propargylic alcohol unit.
We present the first trans-selective diborylation reaction of alkynes. By means of theoretical calculation-assisted reaction analysis, we designed a pseudo-intramolecular reaction of diboron, propargyl alcohol, and a base to facilitate B-B bond activation and C-B bond formation with high efficiency. This approach provides synthetically versatile and densely functionalized 4-borylated 1,2-oxaborol-2(5H)-oles (vinyldiboronates) in a straightforward manner. Detailed computational analysis showed that the directing alkoxide functionality markedly lowers the activation energy of B-C bond formation.
Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yuki
Y
Nagashima
Keiichi
K
Hirano
Ryo
R
Takita
Masanobu
M
Uchiyama
D000480:Alkynes / Q000737:chemistry*; D001897:Boronic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D020005:Propanols / Q000737:chemistry*
D000480:Alkynes; D001897:Boronic Acids; D020005:Propanols; C028255:propargyl alcohol