ol503521b_si_001.pdf (9.64 MB)
Vanadium-Catalyzed Regioselective Oxidative Coupling of 2‑Hydroxycarbazoles
journal contribution
posted on 2016-01-15, 12:06 authored by Lei Liu, Patrick J. Carroll, Marisa C. KozlowskiThe
first regioselective oxidative coupling of 2-hydroxycarbazoles
is described. With a vanadium catalyst and oxygen as the terminal
oxidant, dimers with an ortho–ortho′ coupling pattern
were obtained with high selectivity. Further oxidation led to ortho′–ortho′
coupling to generate a tetramer, which provided insight that the atropisomerization
barriers of the unsymmetrical biaryl bonds are much lower than expected.