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。
Reductive Transformations of Carbonyl Compounds Catalyzed by Rhodium Supported on a Carbon Matrix by using Carbon Monoxide as a Deoxygenative Agent
作者:Niyaz Z. Yagafarov、Dmitry L. Usanov、Alexey P. Moskovets、Nikolai D. Kagramanov、Victor I. Maleev、Denis Chusov
DOI:10.1002/cctc.201500493
日期:2015.9.1
An efficient method for the rhodium on carbon matrix catalyzed preparation of secondary and tertiary amines, cyanoesters, and nitriles through the reductive amination/alkylation of carbonyl compounds was developed, including a convenient procedure for the tandem formal reductive addition of acetonitrile to aldehydes. The catalyst could be reused, and at least three consecutive reaction cycles were
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。
Formal reductive addition of acetonitrile to aldehydes and ketones
作者:Karim Muratov、Ekaterina Kuchuk、Sreekumar Vellalath、Oleg I. Afanasyev、Alexei P. Moskovets、Gleb Denisov、Denis Chusov
DOI:10.1039/c8ob01992d
日期:——
An efficient and highly productive rhodium-catalyzed method for the synthesis of nitriles employing aldehydes or ketones, methyl cyanoacetate, water and carbon monoxide as starting materials has been developed. Simple rhodium chloride without any ligands can be used. The fine tuning of the substrate can lead to the activity higher than 5000 TON.