我们介绍了芳基氰基丙酸酯的超强酸催化的分子内环化反应,以中等至高收率得到环化的五元和六元β-烯胺酯。质子化的腈与芳族碳原子的已知分子内闭环反应限于6元情况。有趣的是,观察到的氰基官能度反应性的显著协同增加,和氰基的氮原子被转化成氨基,当酯基存在于一个孪位的布置。氘交换实验排除了α-质子去质子化在环化过程中的参与。环化反应和13的酸度依赖性在各种酸性介质中对模型化合物氰基乙酸甲酯的13 C NMR研究与强酸中氰基乙酸甲酯的O,N-二质子化指示剂(二元体指示剂)在强酸中的参与一致,这被认为是事实上的亲电子试剂。在本发明的芳基氰基丙酸酯的环化反应中。
Microbial transformation of Knoevenagel adducts by whole cells of Brazilian marine-derived fungi: A green approach to remove organic compounds from the aqueous medium
作者:Lucas Lima Zanin、Thayane Melo de Queiroz、André Luiz Meleiro Porto
DOI:10.1080/10242422.2022.2145556
日期:——
Herein, we report the use of whole cells of Brazilian marine-derived fungi in the biotransformation and biodegradation of organiccompounds, particularly, Knoevenagel adducts. A preliminary screeni...
α-proton in the cyclization process. The acidity dependence of the cyclization reactions and 13C NMR studies of a model compound, methyl cyanoacetate, in various acidic media were consistent with the involvement of the O,N-diprotonated dication of methyl cyanoacetate, a distonic dication, in strong acid, and this is considered to be the de facto electrophile in the present cyclization reaction of arylcyanopropionates
我们介绍了芳基氰基丙酸酯的超强酸催化的分子内环化反应,以中等至高收率得到环化的五元和六元β-烯胺酯。质子化的腈与芳族碳原子的已知分子内闭环反应限于6元情况。有趣的是,观察到的氰基官能度反应性的显著协同增加,和氰基的氮原子被转化成氨基,当酯基存在于一个孪位的布置。氘交换实验排除了α-质子去质子化在环化过程中的参与。环化反应和13的酸度依赖性在各种酸性介质中对模型化合物氰基乙酸甲酯的13 C NMR研究与强酸中氰基乙酸甲酯的O,N-二质子化指示剂(二元体指示剂)在强酸中的参与一致,这被认为是事实上的亲电子试剂。在本发明的芳基氰基丙酸酯的环化反应中。
Direct Cyclopropanation of α‐Cyano β‐Aryl Alkanes by Light‐Mediated Single Electron Transfer Between Donor–Acceptor Pairs
作者:Jing Li、Martin J. Lear、Yujiro Hayashi
DOI:10.1002/chem.202100341
日期:2021.4
formal [2+1] addition of carbene or radical based C1 units to alkenes. In contrast, the one‐pot intermolecular cyclopropanation of alkanes by redoxactive C1 units has remained unrealised. Herein, we achieved this process simply by exposing β‐aryl propionitriles and C1 radical precursors (N‐oxy esters) to base and blue light. The overall process is redox‐neutral and a photocatalyst, whether metal‐ or organic‐based