Metal-Free Oxidative Coupling of Tetrahydroisoquinolines and 3-Fluorooxindoles on Water

An efficient, metal-free oxidative coupling of tetrahydroisoquinolines and 3-fluorooxindoles on water has been developed. Using aqueous tert -butyl hydroperoxide as the oxidant, Et (3) N as the base, and water as the sole solvent, a variety of 3-fluorooxindoles fully substituted at the 3-position and containing a tetrahydroisoquinoline fragment has been successfully prepared in yields of up to 93% with an anti / syn stereo-selectivity of up to 99:1 under very mild and safe reaction conditions.