The non-catalyzed cycloaddition of eight structurally different azides with cyclooctyne generated in situ by the photolysis of cycloocta-1,2,3-selenadiazole gives 1,2,3-triazole derivatives as the main products.
Synthesis and Properties of Palladium Diselenolenes: X-ray Crystal Structures of [Pd{SeC(R<sup>1</sup>)C(R<sup>2</sup>)Se}(PBu<sub>3</sub>)<sub>2</sub>] [R<sup>1</sup>, R<sup>2</sup> = (CH<sub>2</sub>)<i><sub>n</sub></i>, <i>n</i> = 4, 5, 6]
作者:Susan Ford、Christopher P. Morley、Massimo Di Vaira
DOI:10.1021/ic040069y
日期:2004.11.1
The reaction between [Pd(2)(dba)(3)] (dba = dibenzylideneacetone), tributylphosphine, and a bis(cycloalkeno)-1,4-diselenin leads to either a mononuclear diselenolene [Pd[SeC(R(1))=C(R(2))Se](PBu(3))(2)] or a dinuclear diselenolene [Pd(2)[SeC(R(1))=C(R(2))Se](2)(PBu(3))(2)] [R(1), R(2) = (CH(2))(n), n = 4, 5, 6] depending on the stoichiometry employed. Treatment of the dinuclear diselenolenes with 1
treated with an excess amount of olefins at 130°C, the addition of a vinyl radical, which was generated in situ by the denitrogenation of 1,2,3-selenadiazoles, to a carbon–carbon double bond followed by intramolecular cyclization proceeded efficiently giving the corresponding dihydroselenophenenes in moderate to good yields along with the formation of the corresponding 1,4-diselenins and selenophenes
Dinuclear diselenolenes derived from cycloalkeno-1,2,3-selenadiazoles and tetrakis(triphenylphosphine)palladium
作者:Susan Ford、Pawan K. Khanna、Christopher P. Morley、Massimo Di Vaira
DOI:10.1039/a807666i
日期:——
Reaction of [Pd(PPh3)4] with cycloalkeno-1,2,3-selenadiazoles or bis(cycloalkeno)-1,4-diselenines in toluene under reflux led in good yield to the dinuclear diselenolenes [Pd2SeC(R1)C(R2)Se}2(PPh3)2] [R1,R2 = (CH2)n; n = 4, 5, 6] which have been characterised by microanalysis, multinuclear NMR, IR, and mass spectroscopy; the molecular structure of the compound with n = 6 has been determined by X-ray cystallography.
It was found that the reaction of 1,2,3-selenadiazoles derived from cyclic ketones with olefins or dienes was markedly promoted by a catalytic amount of tributylstannyl radical, which was generated in situ from tributylstannyl hydride or allyltributylstannane and AIBN, to give the corresponding dihydroselenophenes in moderate to good yields. In contrast, when 1,2,3-selenadiazoles prepared from linear