A　visible-light-enabled,　photocatalyst-free　conjugate　addition　reaction　of　dehydroamino　acids　is　disclosed.　Employing　4-acyl-1,4-dihydropyridines　as　both　a　radical　reservoir　and　reductant,　various　beta-acyl　alpha-amino　acids　and　their　deuterated　analogues　were　obtained　in　good　results.　Both　late-stage　peptide　modification　and　stereoselective　synthesis　of　chiral　oxazolidinones　are　successfully　achieved.　The　protocol　is　characterized　by　mild　conditions　and　efficient　derivatization,　thus　unlocking　a　novel　blueprint　to　access　unnatural　amino　acid　derivatives,　important　building　blocks　with　potential　application　in　the　peptidomimetic　toolbox.