Well defined dialkyls of the heavier alkaline earth elements, [M{CH(SiMe(3))(2)}(2)(THF)(n)] [M = Ca, n = 2; M = Sr, n = 3; M = Ba, n = 3] react to form either the heteroleptic beta-diketiminato alkyl when M = Ca or unusual 'C-H activation' products in which a methyl group of the ligand is deprotonated when M = Sr or Ba.