C(sp )-H functionalization plays an increasingly important role in the diversification of fine chemicals, providing atom-and step-economic methods to modify complex molecules in a latestage fashion. Hydrogen atom transfer (HAT) represents a particularly appealing approach for C(sp )-H functionalization, enabling the smooth generation of open-shell alkyl radical intermediates from native C(sp 3 )-H bonds, which readily undergo subsequent transformations. Recently, the merger of HAT and photocatalysis has been extensively exploited to forge C-C, C-B, C-O, C-N, C-X (halogen), or C-S bonds from C(sp )-H bonds. Organophosphorus compounds have found wide applications in organocatalysis, medicinal chemistry, 4b and material science. The construction of organophosphorus compounds through HATinduced C-P bond formation directly from readily available alkanes is step-economic and can significantly broaden skeletal diversity of synthetically accessible organophosphorus compounds. However, despite extensive studies in photocatalytic HAT-induced C(sp )-H functionalization, the development of C-P bond formation remains a formidable challenge at the current stage (Figure ). The hurdles include the oxidation-sensitivity of commonly used P(III) and H-P(V) reagents, 5 poor compatibility between P-reagents and electrophilic HAT reagents, low reactivity between nucleophilic alkyl radicals and common Preagents, and the requirement of excess C-H substrates in most intermolecular HAT processes. -Aminophosphonic acids have attracted substantial interests in medicinal chemistry due to their intriguing biological activities 8 (Figure ). The potential utility of -aminophosphonic acids has stimulated significant research efforts aimed at developing efficient protocols for their synthesis. Conventionally, -aminophosphonates were synthesized by the Pudovik reaction, which involves nucleophilic addition of a dialkyl phosphite to an imine under basic conditions. Another powerful method for assembling complex -aminophosphonates is the Kabachnik-Fields reaction, 10 a three-component phospha-Mannich reaction in which an imine is generated in situ from a carbonyl compound and an amine. Recent studies have demonstrated the phosphonylation of N-aryl tertiary amines under photocatalytic and electrocatalytic conditions, initiated by singleelectron oxidation of the tertiary amine. The oxidative phosphonylation of trialkyl amines was also realized by cobalt catalysis and photocatalysis. The decarboxylative phosphonylation of amino acids enabled by photocatalysis has been reported as well. 7b,14 However, these methods either require pre-formed imines, only work with a limited scope of simple tertiary amines, use excess amines, are difficult to be applied to late-stage functionalization, or necessitate the presence of a carboxylic acid as a pre-existing functionality. Consequently, a general and mild protocol for -C(sp 3 )-H phosphonylation of aliphatic amines, which provides direct access to aminophosphonates from a diverse range of amine substrates, remains highly sought after. Photocatalytic HAT-enabled activation of -C(sp 3 )-H bonds of amines has been utilized for diverse -amino C-H functionalization. Building on this, we aimed to develop a general method for -C(sp 3 )-H phosphonylation of amines. To address the incompatibility issue between phosphite reagents and HAT agents, we proposed employing a radical translocating group (T) to trigger a kinetically favored intramolecular HAT event, outcompeting premature intermolecular phosphonylation of the HAT reactive intermediate. Moreover, the photocatalyst adopts an oxidative quenching cycle to generate the corresponding radical cation (PC •+ ), which acts as an oxidant for a radical polar crossover (RPC) process, converting the -aminoalkyl radical to an iminium ion. 14b Finally, a facile Arbuzov-type phosphonylation with trialkyl phosphite furnishes the targeted aminophosphonate (Figure ). Herein we report the successful implementation of the intramolecular-HAT-RPC strategy, establishing a general platform for photocatalyzed HAT-induced phosphonylation of -C(sp 3 )-H of aliphatic amines. For this purpose, 2-Iodobenzoyl group (Bz I ) was chosen as a mild intramolecular HAT reagent. Due to its weakly oxidative nature, Bz I is compatible with oxidation-sensitive phosphite reagents, while fulfilling the requirements for the oxidative quenching cycle.