by one-pot reactions of ketone hydrazones with diselenium dibromide, which suggested the in situ formation of selone and diazoalkane intermediates. The thermolysis of these compounds gave symmetrical olefins, whereas oxidation afforded the corresponding azines. The reaction of acetophenone hydrazones with diselenium dibromide afforded 2,5-diarylselenophenes in moderate yields. The reaction proceeded
Selenoaldehydes and selenoketones were generated in situ, by treating aldehydes or ketones, respectively, with bis(1,5-cyclooctanediylboryl) selenide; the resulting selenocarbonyl compounds were trapped with 2,3-dimethyl-1,3-butadiene to give the corresponding [4+2] cycloadducts. The treatment of amides, an ester, and ketones possessing bulky substituents with the reagent also afforded the corresponding selenoamides, a selenoester, and sterically protected selones, respectively, in modest yields. On the other hand, a similar treatment of cinnamaldehyde with the reagent gave the 2,3-dihydroselenophene derivative, which originated from a [4+2]-type self-dimerization of in situ generated 3-phenyl-2-propeneselenal.
Synthesis of Dialkenyl Dichalcogenides via Alkenechalcogenolate Ions Generated by Treating Ketone p-Toluenesulfonylhydrazones with a Base and Elemental Chalcogen
Alkeneselenolate and alkenetellurolate ions were generated by treating ketone p-toluenesulfonylhydrazones possessing an α-methylene or an α-methine group with t-BuOK and elemental selenium or tellurium, respectively, at 110-150 °C, and were converted into dialkenyl dichalcogenides by aerobic oxidation.
通过分别用 t-BuOK 和元素硒或碲处理具有 α-亚甲基或 α-次甲基基团的酮对甲苯磺酰腙,分别在 110-150 °C 下产生烯硒烯酸和烯四烯酸离子,并通过好氧转化为二烯基二硫属化物氧化。
“Tied-back” carbocyclic intermediates in the preparation of very sterically strained olefins: Derivatives of tetra--butylethylene
作者:Edward R. Cullen、Frank S. Guziec、Mitchell I. Hollander、Christopher J. Murphy
DOI:10.1016/s0040-4039(01)82982-8
日期:1981.1
The preparations of the extremely sterically hindered olefins (12) and-(13) are described, and attempts to convert these compounds to other derivatives of tetra--butylethylene (1) are outlined.
Synthesis and properties of monomeric selenoketones
作者:Thomas G. Back、Derek H. R. Barton、Michael R. Britten-Kelly、Frank S. Guziec
DOI:10.1039/c39750000539
日期:——
The preparation and reactions of di-t-butyl selenoketone (Ib) and of (–)-selenofenchone (IIb) are described; fenchylidenefenchane (VI) has been synthesised.