text: Beryllium derivatives and reagents are often prepared by alkylation of beryllium chloride. Examples of known organoberyllium compounds are dineopentylberyllium, beryllocene (CpBe), diallylberyllium (by exchange reaction of diethyl beryllium with triallyl boron), bis(1,3-trimethylsilylallyl)beryllium and Be(mes)2. Ligands can also be aryls and alkynyls.