Germanium hydrides chiral—

Lastly, Gualtieri reported the use of binaphthyl-substituted germanes (8, 9) in enan-tioselective radical chemistry26. For example, an enantioselectivity of 59% was reported for the reaction of 126 with 8 at —60° (equation 127). To the best of our knowledge, this represents the first account of the use of a chiral germanium hydride in free-radical reduction chemistry. 

The reaction between triorganotin hydrides and organic halides is known since 1957 68). Analogous reactions have been described for chiral triorganosilicon69) and -germanium 70) hydrides, which are stereoselective. It is well known that they proceed via the triorganometal radical, which can also be formed photochemically from metallated ketones 71). 

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