Pd-catalyzed regioselective synthesis of allenyl sulfones via sulfinate-enabled isomerization.

An efficient Pd-catalyzed C-S coupling strategy for the synthesis of tetrasubstituted allenyl sulfones has been developed. Excess sulfinate uniquely acts as both coupling partner and isomerization promoter, driving the in situ generated propargyl sulfone to allenyl sulfone conversion with a high regioselectivity and a broad substrate scope.