ol8b00809_si_001.pdf (2.92 MB)
Unexpected Alkene Isomerization during Iterative Cross-Coupling To Form Hindered, Electron-Deficient Trienes
journal contribution
posted on 2018-05-18, 21:13 authored by Abigail Feceu, Lauren E. Sangster, David B. C. MartinAn iterative cross-coupling
approach to conjugated trienes was
explored as part of a planned stereoselective synthesis of bicyclic
terpenes. Using a bifunctional bromoboronate building block, sequential
Suzuki coupling reactions were employed to provide a conjugated trienone
target containing a tetrasubstituted alkene. During the final cross-coupling
step, an unexpected alkene isomerization was observed to give less
hindered trans products. Examination of different
substrates determined that conjugation to a ketone withdrawing group
was responsible for isomerization, rather than steric hindrance of
the tetrasubstituted alkene.