Novel heterocyclic compounds of the formula I wherein D is wherein R1, R2, E′, E″, E′″, Y″, Y″, G′, G″, G′″ and G′″ have the meaning of claim 1, are activators of glucokinase and can be used for the prevention and/or treatment of Diabetes Typ 1 and 2, obesity, neuropathy and/or nephropathy.