title: Elusive 2H-1,2-oxasiletes through reactions of an isolable dialkylsilylene with diazocarbonyl compounds.
abstract: The reactions of isolable dialkysilylene 1 with 2-diazo-1,2-diphenylethanone and ethyl 2-diazo-2-phenylacetate gave elusive silacycles, 2H-1,2-oxasiletes 2 and 3, respectively, in high yields. Because these reactions occur at low temperatures of ca.-30 °C, initial complexation of the silylene to the carbonyl oxygen of the diazocarbonyl compounds is suggested to trigger dinitrogen elimination followed by cyclization. In contrast, a six-membered cyclic diazo compound 8 and 1-sila-2,3-diazabicyclo[3.3.0]oct-3-ene 10 were obtained in good yields by the reaction of 1 with less reactive ethyl 2-diazo-3-oxo-3-phenylpropanoate 7 and trimethylsilyldiazomethane 9. Molecular structures of 2, 3, 8 and 10 were determined by X-ray crystallography.
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 310012, P. R. China. zhifanglee@hznu.edu.cn mkira@m.tohoku.ac.jp.
authors.forename: Zhaowen
authors.initials: Z
authors.lastname: Dong
authors.forename: Xu-Qiong
authors.initials: XQ
authors.lastname: Xiao
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Li
authors.forename: Qiong
authors.initials: Q
authors.lastname: Lu
authors.forename: Guoqiao
authors.initials: G
authors.lastname: Lai
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kira