Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
作者:Eloi P Coutant、Vincent Hervin、Glwadys Gagnot、Candice Ford、Racha Baatallah、Yves L Janin
DOI:10.3762/bjoc.14.264
日期:——
We have explored here the scope of the age-old diethyl malonate-based accesses to α-aminoesters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered
Lewis Acid-Catalyzed [3+2] Cycloaddition of Donor-Acceptor Cyclopropanes and Enamines: Enantioselective Synthesis of Nitrogen-Functionalized Cyclopentane Derivatives
作者:Kamal Verma、Prabal Banerjee
DOI:10.1002/adsc.201600221
日期:2016.6.30
efficient method for the synthesis of nitrogen‐functionalized cyclopentane derivatives via [3+2] cycloaddition of enamines with donor‐acceptor cyclopropanes in the presence of catalytic amounts of various Lewisacids at room temperature has been developed; furthermore, the corresponding β‐amino acid was synthesized by monodecarboxylation and hydrogenolysis. An enantioenriched synthesis of nitrogen‐functionalized
Intramolecular Friedel–Crafts alkylationreaction of indoles catalyzed by trisoxazoline/copper(II) is described. This annulation provides an easy access to polycyclic indole derivatives with up to 90% ee in up to 99% yield.
Lewis Acid Catalyzed Annulation of Cyclopropane Carbaldehydes and Aryl Hydrazines: Construction of Tetrahydropyridazines and Application Toward a One-Pot Synthesis of Hexahydropyrrolo[1,2-<i>b</i>]pyridazines
作者:Raghunath Dey、Pankaj Kumar、Prabal Banerjee
DOI:10.1021/acs.joc.8b00332
日期:2018.5.18
In this report, a facilesynthesis of tetrahydropyridazines via a Lewis acid catalyzed annulation reaction of cyclopropane carbaldehydes and aryl hydrazines has been demonstrated. Moreover, the generated tetrahydropyridazine further participated in a cycloaddition reaction with donor–acceptor cyclopropanes to furnish hexahydropyrrolo[1,2-b]pyridazines. We also performed these two steps in one pot in
在该报告中,已经证明了通过路易斯酸催化的环丙烷甲醛和芳基肼的环合反应可轻松合成四氢哒嗪。此外,生成的四氢哒嗪进一步与供体-受体环丙烷一起参与环加成反应,提供六氢吡咯并[1,2- b ]哒嗪。我们还在一个锅中以连续的方式执行了这两个步骤。另外,六氢吡咯并[1,2- b ]哒嗪的单脱羧反应得到了良好的收率。
Nickel(II)-Catalyzed Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Alkylidene Malonates
reaction conditions. The reaction could be carried out on a gram scale with the good results being maintained. Control experiments were performed to elucidate the specific diastereoselectivity of the reaction. The formation of single trans isomers was dominated by secondary orbital interactions between the ester groups of the dipolarophile and the azomethineimine. On the basis of the experimental results