Eosin Y as a Direct Hydrogen‐Atom Transfer Photocatalyst for the Functionalization of C−H Bonds

Eosin Y, a well‐known economical alternative to metal catalysts in visible‐light‐driven single‐electron transfer‐based organic transformations, can behave as an effective direct hydrogen‐atom transfer catalyst for C−H activation. Using the alkylation of C−H bonds with electron‐deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y‐based photocatalytic hydrogen‐atom transfer strategy is promising for diverse functionalization of a wide range of native C−H bonds in a green and sustainable manner. Neutrales Eosin‐Y wurde als effektiver, direkter Photokatalysator für den Wasserstoffatomtransfer zur nachhaltigen Aktivierung einer Vielzahl von C‐H‐Bindungen verwendet. Die Transformation ist einfach durchführbar und ermöglicht die Synthese im großen Maßstab mittels kontinuierlicher Fluss‐Technologie (EWG=Aldehyd, Keton, Ester, Amid, Imid, Cyanid, Sulfon, Nitro, Pyridin).