Department of Chemical Sciences, Ariel-University, 40700, Ariel, Israel.
Computational Chemistry Unit, Department of Chemical Research Support, Weizmann Institute of Science, 7610001, Rehovot, Israel.
Angew Chem Int Ed Engl. 2017 Mar 1;56(10):2599-2603. doi: 10.1002/anie.201610274. Epub 2017 Jan 27.
Enolonium species/iodo(III)enolates of carbonyl compounds have been suggested to be intermediates in a wide variety of hypervalent iodine induced chemical transformations of ketones, including α-C-O, α-C-N, α-C-C, and α-carbon-halide bond formation, but they have never been characterized. We report that these elusive umpoled enolates may be made as discrete species that are stable for several minutes at -78 °C, and report the first spectroscopic identification of such species. It is shown that enolonium species are direct intermediates in C-O, C-N, C-Cl, and C-C bond forming reactions. Our results open up chemical space for designing a variety of new transformations. We showcase the ability of enolonium species to react with prenyl, crotyl, cinnamyl, and allyl silanes with absolute regioselectivity in up to 92 % yield.
羰基化合物的烯醇翁物种/碘（III）烯醇盐被认为是各种高价碘诱导的酮的化学转化中的中间体，包括 α-C-O、α-C-N、α-C-C 和 α-碳卤键形成，但它们从未被表征过。我们报告说，这些难以捉摸的未极化烯醇盐可能作为离散物种存在，在 -78°C 下稳定几分钟，并报告了此类物种的首次光谱鉴定。结果表明，烯醇翁物种是 C-O、C-N、C-Cl 和 C-C 键形成反应的直接中间体。我们的结果为设计各种新转化开辟了化学空间。我们展示了烯醇翁物种与烯丙基、巴豆基、肉桂基和烯丙基硅烷反应的能力，在高达 92%的收率下具有绝对区域选择性。
