New phosphonamide compounds and methods of forming those compounds are provided. In one embodiment, the inventive methods comprise subjecting an opened-ring phosphonamide template to a ring-closing metathesis reaction in the presence of a ring-closing catalyst (e.g., a Grubbs catalyst) to yield a phosphonamide. In another embodiment, the inventive methods comprise reacting a template structure with a phosphorus (III) compound to yield the phosphonamide. Advantageously, in either embodiment, the template structures can be provided with a wide array of functional groups (e.g., amino acid side chains, peptides) chosen to provide particular properties to the compound.