Hantzsch Ester-Mediated Photochemical Transformations in the Ketone Series: Remote C(sp3)-H Arylation and Cyclopentene Synthesis through Strain Release.
Hantzsch Ester-Mediated Photochemical Transformations in the Ketone Series: Remote C(sp3)-H Arylation and Cyclopentene Synthesis through Strain Release.
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Hantzsch 酯介导的酮系列光化学转化：通过应变释放远程 C(sp3)-H 芳基化和环戊烯合成
DOI：
10.1021/acs.joc.0c02591
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
T. Opatz
中科院分区：
文献类型：
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作者：
J. Paternoga;J. Kühlborn;N. O. Rossdam;T. Opatz
以酮基环丙烷为原料，在Hantzsch酯催化下，在环境友好的条件下合成了环戊烯基酮和γ-杂芳基酮。所开发的条件的通用性示出通过反应酮环丙烷在两个正式的[3 + 2]环加成与末端炔（进一步研究使用理论计算）和自由基C-C-耦合与氰基吡啶。新开发的方法后来被用作结合UV和可见光光化学的光生环丙烷的下游反应。在此过程之后，UV驱动的Norrish-Yang型反应诱导中间体的环应变，其作为随后的环转化的活化能。
A metal-free Hantzsch ester-mediated synthesis of cyclopentenylketones as well as γ-hetarylketones starting from ketocyclopropanes under eco-friendly conditions was developed. The versatility of the developed conditions is shown by reacting ketocyclopropanes in both a formal [3 + 2] cycloaddition with terminal alkynes (further investigated using theoretical calculations) and a radical C–C-coupling with cyanopyridines. The newly developed methodologies were later on utilized as a downstream reaction for photogenerated cyclopropanes combining UV and visible light photochemistry. Following this procedure, a UV-driven Norrish–Yang-type reaction induces the ring strain of the intermediates, which serves as activation energy for the subsequent ring transformation.