Diastereoselective Radical Tandem Addition‐Cyclization Reactions of Aromatic Tertiary Amines by Semiconductor‐Sensitized Photochemical Electron Transfer

The diastereoselective radical tandem addition‐cyclization reaction of N , N ‐dimethylaniline ( 2 ) with menthyloxyfuranone 1 was initiated by photochemically induced electron transfer using inorganic semiconductors (TiO 2 , ZnS, SiC and SnO 2 ) as sensitizers. The rearomatization step, which also causes the partial reduction of 1 , was studied by isotopic labeling experiments using deuterated derivatives of 2 . The influence of the semiconductor surface on these processes has been characterized and compared with the results obtained under homogeneous conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)