Diphenyldiazomethane regioselectively adds to 2-R-substituted maleimides to yield 1-pyrazoline derivatives, 1-R-7-aryl-6,8-dioxo-4,4-Biphenyl-2,3,7-triazabicyclo[3.3.0]oct-2-enes that on heating liberate nitrogen to afford substituted 3-azabicyclo[3.1.0]hexanes. To the N-arylsubstituted imides of itaconic acid the diphenyldiazomethane adds to furnish 5-aryl-4,6-dioxo-1,1-Biphenyl-5-azaspiro[2.4]heptanes.
N-Primary-amine tetrapeptide-catalyzed highly asymmetric Michael addition of aliphatic aldehydes to maleimides
作者:Zhi-Hong Du、Wen-Juan Qin、Bao-Xiu Tao、Meng Yuan、Chao-Shan Da
DOI:10.1039/d0ob01457e
日期:——
highly asymmetric Michaeladdition reaction between maleimides and aliphatic aldehydes catalyzed by low-loading β-turn tetrapeptides with excellent yields and enantioselectivities at room temperature was reported. α-Branched and α-unbranched aldehydes both are suitable nucleophiles. N-Aryl, alkyl and hydrogen maleimides all are well tolerated and led to high yields and enantioselectivities. The transformation
作者:Zhiyu Xie、Fei Li、Liangfeng Niu、Hongbing Li、Jincai Zheng、Ruijing Han、Zhiyu Ju、Shanshan Li、Dandan Li
DOI:10.1039/d0ob01403f
日期:——
cycloaddition–aromatization cascade was realized with N-substituted tetrahydroisoquinolines and electron-deficient olefins. Under the mild conditions, the reaction proceeded smoothly and displayed excellent functional group tolerance, affording 5,6-dihydro-pyrrolo[2,1-a]isoquinolines in good to high yields. This protocol exhibits a broad substrate scope to both N-alkyl tetrahydroisoquinolines and dipolarophile
用N-取代的四氢异喹啉和缺电子烯烃实现了高效且环保的CuBr/NHPI共催化好氧氧化[3 + 2]环加成-芳构化级联。在温和条件下,反应顺利进行,并表现出优异的官能团耐受性,以良好至高收率得到5,6-二氢-吡咯并[2,1- a ]异喹啉。该协议对N-烷基四氢异喹啉和亲偶极底物都表现出广泛的底物范围。
Aerobic Oxidative EDA Catalysis: Synthesis of Tetrahydroquinolines Using an Organocatalytic EDA Active Acceptor
作者:August Runemark、Henrik Sundén
DOI:10.1021/acs.joc.1c02776
日期:2022.1.21
A catalytic electron donor–acceptor (EDA) complex for the visible-light-driven annulation reaction between activated alkenes and N,N-substituted dialkyl anilines is reported. The key photoactive complex is formed in situ between dialkylated anilines as donors and 1,2-dibenzoylethylene as a catalytic acceptor. The catalytic acceptor is regenerated by aerobic oxidation. Investigations into the mechanism
Organocatalytic Asymmetric Michael/Cyclization Cascade Reaction of 3-Isothiocyanato Oxindoles with Maleimides for the Efficient Construction of Pyrrolidonyl Spirooxindoles
作者:Lei Liu、Bo-Liang Zhao、Da-Ming Du
DOI:10.1002/ejoc.201600658
日期:2016.9
The development of a Michael/cyclization cascadereaction between 3-isothiocyanato-oxindoles and maleimide catalyzed by chrial squaramides is reported. This protocol provides a series of pyrrolidonyl spirooxindoles bearing three contiguous stereocenters in excellent yields (up to 99 %) with high diastereo- and enantioselectivities (up to >99:1 dr, 91 % ee).
Heterocyclization reactions between N-arylmaleimides and 6-aminouracils were studied in detail. It was established that several directions are possible depending on the nature of reaction medium and the substituent character in the uracil component. The synthetic procedure leading to N-phenyl-2,4,7-trioxopyrido[2,3-d]pyrimidine-5-carboxamides in good-to-high yields was developed and key stages of the corresponding reaction were established.