Palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with 1-alkenyl halides or triflates: convenient synthesis of unsymmetrical 1,3-dienes via the borylation-coupling sequence.
The synthesis of 1-alkenylboronic acid pinacol esters via a palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron (pin(2)B(2), pin = Me(4)C(2)O(2)) with 1-alkenyl halides or triflates was carried out in toluene at 50 degrees C in the presence of KOPh (1.5 equiv) and PdCl(2)(PPh(3))(2)-2Ph(3)P (3 mol %). The borylation of acyclic and cyclic 1-alkenyl bromides and triflates was achieved in high yields with complete retention of configuration of the double bonds. The method was applied to the one-pot synthesis of unsymmetrical 1,3-dienes via the borylation-coupling sequence.
Takagi
Jun
J
Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Takahashi
Kou
K
Ishiyama
Tatsuo
T
Miyaura
Norio
N
D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D002074:Butanones / Q000138:chemical synthesis*; D002384:Catalysis; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D008698:Mesylates / Q000737:chemistry; D010165:Palladium / Q000737:chemistry
D000475:Alkenes; D001896:Boron Compounds; D002074:Butanones; D006846:Hydrocarbons, Halogenated; D008698:Mesylates; C463639:bis(pinacolato)diboron; D010165:Palladium; C012077:trifluoromethanesulfonic acid