An efficient, metal-free oxidative coupling of tetrahydroisoquinolines and 3-fluorooxindoles on water has been developed. Using aqueous tert-butyl hydroperoxide as the oxidant, Et3N 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 stereoselectivity of up to 99:1 under very mild and safe reaction conditions.
Key words
fluorine - fluoroalkylation - oxidative coupling - water - green synthesis