Regioselective aromatic borylation in an inert solvent.
[reaction: see text]. A protocol for performing Rh catalyzed aromatic borylations in cyclohexane has been devised. Borylation at the 5-position of several 1,3-substituted aromatic species ranging from electron-rich (1,3-(NMe(2))(2)C(6)H(4)) to electron-deficient (1,3-(CF(3))(2)C(6)H(4)) yields the corresponding aryl boronate esters. Veratrole was selectively borylated at the 4-position, thus extending regioselectivity to 1,2-substituted benzenes. Selective borylation at the 3-position of an N-protected pyrrole has also been demonstrated, providing a valuable reagent for cross-coupling reactions in a single step.
Tse
M K
MK
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Cho
J Y
JY
Smith
M R
MR
D000840:Anisoles / Q000737:chemistry*; D003510:Cyclohexanes / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry*
D000840:Anisoles; D003510:Cyclohexanes; C005299:veratrole; D012238:Rhodium