Department of Medicinal Chemistry, University of Kansas, Lawrence, 66045, KS, USA.
Department of Chemistry, University of Kansas, Lawrence, 66045, KS, USA.
Angew Chem Int Ed Engl. 2023 Jan 16;62(3):e202215856. doi: 10.1002/anie.202215856. Epub 2022 Dec 13.
Photoexcitation of cyclic ketones leads to the expulsion of carbon monoxide and a mixture of products derived from diradical intermediates. Here we show that synthetic utility of this process is improved if strained heterocyclic ketones are used. Photochemistry of 3-oxetanone and N-Boc-3-azetidinone has not been previously described. Decarbonylation of these 4-membered rings proceeds through a step-wise Norrish type I cleavage of the C-C bond from the singlet excited state. Ylides derived from both compounds are high-energy species that are kinetically stable long enough to undergo [3+2] cycloaddition with a variety of alkenes and produce substituted tetrahydrofurans and pyrrolidines. The reaction has a sufficiently wide scope to produce scaffolds that were either previously inaccessible or difficult to synthesize, thereby providing experimental access to new chemical space.
环酮的光激发导致一氧化碳的排出和由双自由基中间体衍生的产物的混合物。在这里，我们表明，如果使用应变杂环酮，此过程的合成实用性会得到提高。3-氧杂环丁酮和 N-Boc-3-氮杂环丁酮的光化学以前没有被描述过。这些四元环的脱羰反应是通过从单重激发态逐步进行 Norrish 型 I 裂解 C-C 键来进行的。两种化合物衍生的叶立德都是高能物质，它们在动力学上足够稳定，可以与各种烯烃进行[3+2]环加成反应，生成取代的四氢呋喃和吡咯烷。该反应具有足够广泛的范围，可以生成以前无法获得或难以合成的支架，从而为新的化学空间提供了实验途径。
