Remote C-H activation of phenyl-substituted alkenes by BH(3).THF: mechanism and applications.

[reaction: see text] The hydroboration of tetrasubstituted alkenes and, in particular, bicyclic alkenes with BH(3).THF at 50 degrees C provides, via a highly stereoselective 1,2-rearrangement and a remote C-H activation, a diol in which the relative stereochemistry of three centers has been controlled. A mechanistic study provides general rules for remote C-H activation and leads to new synthetic applications.