NICKEL-CATALYZED SUBSTITUTIONS OF ARYL TERT-BUTYL SULFONES WITH ORGANOMETALLIC REAGENTS - SYNTHESIS OF ORTHO-SUBSTITUTED UNSYMMETRICAL BIARYLS

In the presence of a catalytic amount of a nickel salt, aryl tert-buty l sulfones react with aryl Grignard reagents to give biaryls. This rea ction is used in conjunction with the powerful ortho-lithiation-direct ing ability of aryl tert-butyl sulfonyl groups to make-unsymmetrical o rtho-substituted biaryls. In certain cases, the substitution of an ary l alkylsulfonyl group by an organometallic reagent is possible without a Transition metal catalyst.