1994 年 42 巻 12 号 p. 2441-2448
Flash vacuum pyrolysis of 2a, 7b-dihydrocyclobuta[b]-1-benzometalloles (6a-e), prepared from the corresponding 1-benzometalloles (3) containing Si, Ge, P, or As via three steps, resulted in valence isomerization with ring-opening to give 1, 1-dimethyl-1-benzosilepine (7a), 1-methyl-1-phenyl-1-benzosilepine (7b), 1, 1-dimethyl-1-benzogermepine (7c), 1-phenyl-1-benzophosphepine 1-oxide (7d), and 1-phenyl-1-benzarsepine 1-oxide (7e). The oxides (7d, e), on treatment with trichlorosilane, underwent deoxygenation to afford 1-phenyl-1-benzophosphepine (7f) and 1-phenyl-1-benzarsepine (7g). The 1-benzometallepines (7a-g) thus obtained are hitherto unknown heterocyclic ring compounds, and their thermal stabilities and several reactions were examined.
