Sa nium 1, l-bimetallic reagents. In the course of our continuing studies on the reactivity of 1, l-bimetalloalkanes of zinc and magnesium, 2 we needed a more general preparation of these reagents3 allowing the access to a variety of carbon skeletons. Our attention was drawn to the pioneering work of J. S~ hwartz,'j-~~~ who demonstrated that various alkenyl organometallics can be hydrometallated leading to several new classes of 1, l-bimetallic ...