School of Chemical and Materials Engineering, Huainan Normal University, Huainan, Anhui 232038, P. R. China.
Hefei National Laboratory for Physical Science at the Microscale, Department of Chemistry, Center for Excellence in Molecular Synthesis, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Org Lett. 2021 Oct 1;23(19):7364-7369. doi: 10.1021/acs.orglett.1c02514. Epub 2021 Sep 20.
Aldehydes and aziridines are both intrinsic electrophilic reagents, and thus the coupling reaction between these two compounds is highly challenging. In this protocol, the merger of nickel and hydrogen-atom-transfer photocatalysis successfully enables the ring opening of -tosyl styrenyl aziridines with aldehydes, providing a novel and atom-economical access to a variety of β-amino ketones with complete regiocontrol. The preliminary mechanistic studies reveal that the ring opening reaction proceeds with a cooperative catalytic mode: aldehydes are converted into acyl radicals by tetrabutylammonium decatungstate under irradiation, whereas the nickel catalyst is engaged in the ring opening of aziridines and the following carbon-carbon bond-forming step.
醛和氮丙啶都是内在的亲电试剂，因此这两种化合物的偶联反应极具挑战性。在本方案中，镍和氢原子转移光催化的结合成功实现了对 -甲苯磺酰基苯乙烯基氮丙啶与醛的开环反应，为各种β-氨基酮提供了一种新颖且原子经济性的方法，具有完全的区域选择性。初步的机理研究表明，开环反应以协同催化模式进行：醛在辐射下被四丁基铵十钨酸盐转化为酰基自由基，而镍催化剂则参与氮丙啶的开环以及随后的碳-碳键形成步骤。
