110569-30-7Relevant articles and documents
Electron-Transfer Photochemistry of Benzocyclobutenes. - Stereospecific Electrocyclic Reactions of their Cation Radicals
Takahashi, Yasutaka,Kochi, Jay K.
, p. 253 - 270 (2007/10/02)
The facile activation of cis- and trans-1,2-diphenylbenzocyclobutene (DBC) either by charge-transfer irradiation of the electron donor-acceptor complex with tetracyanoethylene or by chloranil photosensitization leads to a series of rapid cycloadditions.The role of the cation radical DBC(+*) as the reactive intermediate which undergoes a stereospecific, conrotatory cycloreversion is delineated, especially with regard to "contact" and "solvent-separated" ion pairs.Such cycloadditions induced by electron transfer are discussed in the contex of the thermal valence tautomerization of DBC previously established by Huisgen, Quinkert, and co-workers.