Compounds are provided which are phosphonate and phosphinate activators and thus are useful in treating diabetes and related diseases and have the structure wherein is a heteroaryl ring; R.sub.4 is --(CH.sub.2).sub.n-Z-(CH.sub.2).sub.m--PO(OR.sub.7)(OR.sub.8), --(CH.sub.2).sub.nZ-(CH.sub.2).sub.m--PO(OR.sub.7)R.sub.g, --(CH.sub.2).sub.n-Z-(CH.sub.2).sub.m--OPO(OR.sub.7)R.sub.g, --(CH.sub.2).sub.nZ--(CH.sub.2).sub.m--OPO(R.sub.9)(R.sub.10), or --(CH.sub.2).sub.nZ--(CH.sub.2).sub.m--PO(R.sub.9)(R.sub.10); R.sub.5 and R.sub.6 are independently selected from H, alkyl and halogen; Y is R.sub.7(CH.sub.2).sub.s or is absent; and X, n, Z, m, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and s are as defined herein; or a pharmaceutically acceptable salt thereof. A method for treating diabetes and related diseases employing the above compounds is also provided.