Preparation of functionalized organomanganese(II) reagents by direct insertion of manganese to aromatic and benzylic halides.

Functionalized arylmanganese compounds were prepared using commercial manganese powder in the presence of LiCl and catalytic amounts of both 2.5% InCl(3) and 2.5% PbCl(2) (THF, 0-50 °C). In addition, benzylic manganese reagents are obtained at 25 °C in ca. 70-80% yield (in the absence of LiCl) using commercial manganese powder and catalytic amounts of 2.5% InCl(3) and 2.5% PbCl(2). The resulting organomanganese reagents undergo smooth 1,2-addition, acylation, allylic substitution, Pd-catalyzed cross-coupling, and copper-catalyzed conjugate addition, affording the desired products in good yields.