Benzyltriboronates: Building Blocks for Diastereoselective Carbon-Carbon Bond Formation.
A highly diastereoselective carbon-carbon bond-forming reaction involving the tandem coupling of benzyltriboronates, enoates, and alkyl halides is described. This method was enabled by the discovery of α-diimine nickel catalysts that promote the chemoselective triborylation of benzylic C(sp3)-H bonds using B2Pin2(Pin = pinacolate). The C-H functionalization method is effective with methylarenes and for the diborylation of secondary benzylic C-H bonds, providing direct access to polyboron building blocks from readily available hydrocarbons. Combination of the benzylic perborylation with a new deborylative conjugate addition-alkylation method enables a one-pot procedure in which multiple simple precursors are combined to generate diastereopure products containing quaternary stereocenters.
Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
W Neil
WN
Palmer
Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
Cayetana
C
Zarate
Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
Paul J
0000-0001-8473-2898
PJ
Chirik