P. Wessig, S. Krebs
N-Aroylsulfonamide-Photofragmentation (ASAP) - A versatile route to biaryls
Eur. J. Org. Chem. 2021, 6367-6374
DOI: 10.1002/ejoc.202100955
The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The mechanism of the ASAP was elucidated by interaction of photophysical and quantumchemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
Zurück zur Übersicht »