trisacetonitrile hexafluorophosphate 4, the Alder-ene type reaction of alkenes and internalalkynes provides an effective way to synthesize trisubstituted alkenes. Unlike most typical olefination protocols, this reaction is atom economical, and affords trisubstituted alkenes with defined olefin geometry. The regioselectivity can be explained invoking a steric argument based on the proposed mechanism. The
in good to excellent isolated yields from carbonyl compounds by converting the carbonyl functionality into the enol nonaflate intermediate followed by elimination to give the C-C triple bond. The one-pot transformations were uniformly induced by phosphazene bases combined with mildly electrophilic nonafluorobutane-1-sulfonyl fluoride. The method is the most general among those reported to date as it
通过将羰基官能团转化为烯醇九氟甲磺酸酯中间体,然后消除以得到 CC 三键,从羰基化合物中以良好至极好的分离产率获得了末端和内部乙炔。磷腈碱与温和亲电子的九氟丁烷-1-磺酰氟相结合均匀地诱导了一锅法转化。该方法是迄今为止报道的方法中最通用的,因为它适用于无环酮和醛。只有适度的动力学区域选择性有利于从甲基正烷基酮实现的 alk-1-yne 代表了该方法的局限性。在所有其他情况下,都获得了单独的炔烃产品。
A convenient synthesis of 1- and 2-alkynes
作者:J. Klein、E. Gurfinkel
DOI:10.1016/s0040-4020(01)92790-5
日期:1970.1
Terminal olefins are transformed by bromination and subsequent dehydrobromination at room temperature with a solution of sodamide or sodium hydride in DMSO to pure terminal acetylenes. trans Dehydrobromination of vinylic bromides proceeds faster than the cis. Conditions were found, where the 1-alkynes are converted into 2-alkynes.
Propargylic Oxidations Catalyzed by Dirhodium Caprolactamate in Water: Efficient Access to α,β-Acetylenic Ketones
作者:Emily C. McLaughlin、Michael P. Doyle
DOI:10.1021/jo800382p
日期:2008.6.1
hydroperoxide (T-HYDRO) is a highly effective catalytic oxidation protocol for the selective C−H oxidation of alkynes to propargylic ketones. The oxidation occurs readily in aqueous solvent under mild conditions with an inexpensive and easily handled oxidant. α,β-Acetylenic carbonyl compounds are formed in up to 80% isolated yield.