Effect of aryl substituents on intramolecular cyclizations of 3,3′,5,5′-tetraaryl-2,2′-biphenoquinones (Ar = phenyl (la) and 4-methoxyphenyl (1b)) has been studied. In benzene, 1a gave 2,4,6,8-tetraphenyldibenzofuran-1-ol (10) gradually as a main product, indicating the phenyl substituents preferred to stabilize the intermediate by derealization of the negative charge rather than that of the positive one. In contrast, the reaction of 1b occurred spontaneously in order to give a complex mixture, which should be due to 4-methoxyphenyl substituent at the 3 position.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Organic Chemistry