864067-07-2Relevant academic research and scientific papers
The exo-outstretching effect governing the exclusive stereoselectivity of the intramolecular [2 + 2] photocycloaddition of vinylarenes
Nishimura, Jun,Funaki, Takashi,Saito, Noriaki,Inokuma, Seiichi,Nakamura, Yosuke,Tajima, So,Yoshihara, Toshitada,Tobita, Seiji
, p. 1226 - 1239 (2007/10/03)
Intramolecular [2 + 2] photocycloaddition of a dimeric vinylpyridine 1 through a singlet-excited species efficiently formed the corresponding syn- and anti-pyridinophanes 2 and 3. The syn-isomers were elucidated spectroscopically and by X-ray crystallography as exo,syn-configured. The high selectivity under formation of exo,syn-2 was thoroughly investigated. Consequently, an exo-outstretching effect, which is observed around the periphery of a face-to-face-oriented system between two aromatic nuclei as a transition state, on cyclobutane ring formation was discovered for the first time.
