Arylative Allenol Cyclization via Sequential One‐pot Enzyme & Palladium Catalysis
Janne M. Naapuri, Gustav A. Åberg, José M. Palomo, Jan Deska
Abstract
Abstract The one‐pot combination of halogenation biocatalysis and Suzuki‐type cross coupling enables the direct arylative cyclization of allenic alcohols with boronic acids. This modular approach to unsaturated five‐membered O ‐heterocycles proceeds in an aqueous emulsion with air as terminal oxidant. Here, the enzymatic oxidative activation of simple halide salts acts as traceless ring‐closure‐inducing event to trigger the subsequent C−C coupling. With the original protocol merging soluble proteins and a homogeneous SPhos‐based palladium catalyst as a template, a novel heterogeneous nanobiohybrid was developed. Consisting of an oxidase matrix hosting small spherical palladium nanoparticles, this enzyme‐metal hybrid exhibits catalytic competence for both the biocyclization as well as the C−C bond‐forming cross coupling, underlining the potential of this new techniques for streamlining chemoenzymatic approaches.