Photoreactions of several arylalkylcyclopropenethiones (1b-e) have been investigated. The products formed have been rationalized on the basis of α-cleavage as the primary photoprocess. The photochemical α-cleavage is presumed to originate from the lowest excited nπ* triplet state. A regioselective α-cleavage reaction has been observed and this unusual regioselectivity is explained on the basis of close approach of the ground-state energy surface of the diradical/carbene, the primary intermediates, to the excited triplet-state surface of cyclopropenethiones. Reactions originating from both triplet and singlet thioketene carbene have been observed upon photolysis of arylalkylcyclopropenethiones.
ASJC Scopus subject areas
- Organic Chemistry