This study reports an efficient electroreduction method for unactivated alkyl alkenes using water as a hydrogen source. The process involves the use of a catalytic amount of chlorosilane, which acts as a hydrogen carrier to generate a highly active silane species under electrochemical conditions. The method enables the hydrogenation of a broad range of substrates with good functional group compatibility. Additionally, the use of deuterated water (D₂O) allows for the production of deuterated products with excellent deuterium incorporation (up to >99%). The approach also demonstrates potential in the pharmaceutical industry through the late-stage hydrogenation of complex molecules and drug derivatives. Mechanistic studies support the role of chlorosilane as a hydrogen carrier and reveal the involvement of both iron and nickel catalytic cycles in the transformation. The method is efficient, cost-effective, and environmentally friendly, utilizing iron as a dual-function anode and in situ hydrogen source. The study highlights the potential of electrochemical methods in organic synthesis, particularly for the hydrogenation of unactivated alkenes.This study reports an efficient electroreduction method for unactivated alkyl alkenes using water as a hydrogen source. The process involves the use of a catalytic amount of chlorosilane, which acts as a hydrogen carrier to generate a highly active silane species under electrochemical conditions. The method enables the hydrogenation of a broad range of substrates with good functional group compatibility. Additionally, the use of deuterated water (D₂O) allows for the production of deuterated products with excellent deuterium incorporation (up to >99%). The approach also demonstrates potential in the pharmaceutical industry through the late-stage hydrogenation of complex molecules and drug derivatives. Mechanistic studies support the role of chlorosilane as a hydrogen carrier and reveal the involvement of both iron and nickel catalytic cycles in the transformation. The method is efficient, cost-effective, and environmentally friendly, utilizing iron as a dual-function anode and in situ hydrogen source. The study highlights the potential of electrochemical methods in organic synthesis, particularly for the hydrogenation of unactivated alkenes.