An intermolecular anti-Markovnikov hydroamination of alkenes has been developed using triethyl phosphite and N-hydroxyphthalimide. The process tolerates a wide range of alkenes, including vinyl ethers, silanes, and sulfides as well as electronically unbiased terminal and internal alkenes. The resultant N-alkylphthalimides can readily be transformed to the corresponding primary amines. Mechanistic probes indicate that the process is mediated via a phosphite promoted radical deoxygenation of N-hydroxyphthalimide to access phthalimidyl radicals.