Rapid and Regioselective Hydrogenation of α,β-Unsaturated Ketones and Alkylidene Malonic Diesters Using Hantzsch Ester Catalyzed by Titanium Tetrachloride
作者:Yulin Lam、Jun Che
DOI:10.1055/s-0030-1258556
日期:2010.10
A regioselective hydrogenation of α,β-unsaturated ketones and alkylidenemalonic diesters using Hantzsch ester as the reducing agent and titanium tetrachloride as a catalyst is described. The short reaction times and mild reaction conditions are the advantages of this method.
Chiral-Zn(NTf<sub>2</sub>)<sub>2</sub>-Complex-Catalyzed Diastereo- and Enantioselective Direct Conjugate Addition of Arylacetonitriles to Alkylidene Malonates
Chiral N,N′‐dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetricconjugateaddition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate‐to‐good yields with high diastereoselectivities (82:18–>99:1 d.r.) and enantioselectivities (81–99 % ee). The reactions
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
Various kinds of 3-substituted (E)-2-(hydroxymethyl)prop-2-enyl acetates were conveniently obtained in excellent yields by the regiospecific acetylation of 2-alkylidenepropane-1,3-diols with 10 equivalents of vinyl acetate in the presence of 50% w/w porcine pancreatic lipase (PPL) type II; the starting materials or (Z)-monoacetate or diacetate byproducts were generally not present.