hydrofunctionalizationthe

Hydrofunctionalization is a class of chemical transformations in which a hydrogen atom and a functional group are added across an unsaturated substrate, such as an alkene or alkyne, in a single operation. The process converts a multiple bond into two new sigma bonds, enabling rapid installation of heteroatom or carbon substituents while simultaneously saturating the substrate. Hydrofunctionalization encompasses a family of reactions including hydroamination (addition of hydrogen and an amino group to form amines), hydroalkoxylation (formation of alcohols or ethers through addition of OH or OR), hydrohalogenation (addition of hydrogen and a halogen), hydroboration (borylation across the bond followed by oxidation to yield alcohols), and hydrosilylation (silicon–hydrogen addition). These methods can operate on alkenes, alkynes, and conjugated systems, enabling the formation of C–N, C–O, C–X, or C–C bonds under relatively mild conditions compared with multi-step routes.

Mechanistically, hydrofunctionalization can proceed via metal-catalyzed pathways, often employing transition metals such as nickel, palladium, copper, rhodium, or iron, and hydrogen donors including H2, silanes, or boranes. Alternative radical or photochemical routes are also explored. Catalyst design, ligands, and directing groups influence regio- and stereoselectivity, allowing anti-Markovnikov or Markovnikov outcomes and, in some cases, enantioselective variants.

Applications of hydrofunctionalization include the streamlined synthesis of complex amines, alcohols, and ethers from simple precursors, as well as late-stage functionalization of advanced substrates. It also supports utility in polymer chemistry and pharmaceutical synthesis. Ongoing research aims to expand substrate scope, improve selectivity, and reduce reliance on costly or sensitive catalysts.