LiCl-mediated preparation of highly functionalized benzylic zinc chlorides.

In the presence of zinc dust (1.5-2.0 equiv) and LiCl (1.5-2.0 equiv), various benzylic chlorides bearing functional groups (iodide, cyanide, ester, ketone) are smoothly converted at 25 degrees C to the corresponding zinc reagents without homo-coupling (<5%). The utility of these benzylic zinc reagents is demonstrated by a short synthesis of papaverine.