Differentially protected diboron for regioselective diboration of alkynes: internal-selective cross-coupling of 1-alkene-1,2-diboronic acid derivatives.
A differentially protected diboron bearing the naphthalene-1,8-diaminato group on one of the two boron atoms undergoes highly regioselective diboration with terminal alkynes in the presence of Pt or Ir catalysts, giving 1-alkene-1,2-diboronic acid derivatives in which the less reactive B(dan) group is located at the terminal position. The products undergo selective Suzuki-Miyaura coupling with aryl bromides at the internal boronyl group, leading to the formation of 2,2-disubstituted alkenylboronic acid derivatives.
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Noriyuki
N
Iwadate
Michinori
M
Suginome