Reduktionspfade

Reduktionspfade is a term used in chemistry and biochemistry to describe sequences of reduction steps that convert a substrate into more reduced forms. The concept emphasizes the order and selectivity of reductions, often planned as a chain of transformations where each step is compatible with existing functionalities.

In organic synthesis, Reduktionspfade refer to the strategic sequence of reductions used to build a target molecule from a more oxidized precursor. The choice of reagents and conditions must consider chemoselectivity, stereoselectivity, and protecting-group strategy. Common transformations include reduction of carbonyl groups (aldehydes and ketones) to alcohols, reduction of alkenes to alkanes, and reduction of nitro groups to amines. Reducing agents range from hydride donors like sodium borohydride and lithium aluminum hydride to catalytic hydrogenation with hydrogen over metal catalysts, and transfer hydrogenation. Electrochemical reductions and catalytic hydride-transfer processes are also employed.

In biochemistry, reductive pathways describe enzyme-catalyzed routes that transfer electrons to reduced cofactors such as NADH or FADH2, driving downstream reductions essential for metabolism. Examples include fatty acid and sugar biosynthesis, and anaerobic respiration steps that reduce electron acceptors.

Key considerations in Reduktionspfade are selectivity against multiple reducible sites, the potential for over-reduction, and the compatibility of the steps with later transformations. Understanding these paths helps chemists design efficient, scalable syntheses and biochemists map metabolic fluxes.