High-yield formation of allylic germanes by Pd-2(dba)(3)-catalyzed reaction of allylic halides with digermanes

Hexaethyl-, hexamethyl-, 1,2-dibenzyltetramethyl-, 1,2-diphenyltetraethyl-, 1,2-diphenyltetramethyl-, 1,2-dichlorotetraethyl- and 1,2-dichlorotetramet hyldigermane react with allylic halides in the presence of a palladium-dibe nzylideneacetone complex as the catalyst to produce regio- and stereoselect ively allylgermanes in good to high yields. For the reaction of the unsym-d igermanes such as phenylpentaethyl- or phenylpentamethyldigermane with the allyl halides, the corresponding allylphenylgermanes are metal-selectively produced in good yields. The reactivities of the digermanes toward an allyl chloride are in the following order: (CIMe2Ge)(2) (r.t., 4 h) approximate to (PhMe2Ge)(2) (r.t., 5 h) > (PhEt2Ge)(2) (r.t., 25 h) > (BnMe2Ge2)(2) (r. t., 50 h) approximate to (Me3Ge)(2) (r.t., 50 h) > (CIEt2Ge)(2) (r.t., 84 h ) > (Et3Ge)(2) (120 degreesC, 20 h).