Me<sub>2</sub>Zn-Mediated Addition of Acetylenes to Aldehydes and Ketones
作者:Pier Giorgio Cozzi、Jens Rudolph、Carsten Bolm、Per-Ola Norrby、Claudia Tomasini
DOI:10.1021/jo050115r
日期:2005.7.1
Contrary to expectations, commercially available 2 M Me2Zn in toluene is able to promote the addition of phenylacetylene to aldehydes and ketones. This reactivity is determined by a new, unprecedented mechanism, which involves activation of the zinc reagent via coordination with carbonyl substrates that behave “ligand like”. Broad scope, high tolerance to functional groups, and a simple procedure make
与预期相反,在甲苯中可商购的2 M Me 2 Zn能够促进将苯乙炔添加到醛和酮中。这种反应性是由一种新的,前所未有的机制决定的,该机制涉及通过与表现为“配体样”的羰基底物的配位来激活锌试剂。宽泛的范围,对官能团的高度耐受性以及简单的操作步骤使这种新方法对于合成化学家而言非常有趣。
Brønsted Acid Catalyzed C3-Selective Propargylation and Benzylation of Indoles with Tertiary Alcohols
A Brønsted acid catalyzed C3-selective tert-alkylation of indoles using tertiary propargylic and benzylic alcohols has been developed. New C3-propargylated indole derivatives with a quaternary carbon at the propargylic position have been efficiently synthesized. Reactions were performed in air with undried solvents, and water was the only side product of the process.
Lewis Acid-Catalyzed Cyclization of Enaminones with Propargylic Alcohols: Regioselective Synthesis of Multisubstituted 1,2-Dihydropyridines
作者:Yushang Shao、Kai Zhu、Zhengchen Qin、Ende Li、Yanzhong Li
DOI:10.1021/jo4005553
日期:2013.6.7
A highly efficient BF3·Et2O-catalyzed cascade reaction of enaminones with propargylicalcohols under mild reaction conditions has been developed. This methodology offers regioselective access to multisubstituted 1,2-dihydropyridines in good to excellent yields.
Organocatalytic Formal (3 + 2) Cycloaddition toward Chiral Pyrrolo[1,2-<i>a</i>]indoles via Dynamic Kinetic Resolution of Allene Intermediates
作者:Jian-Fei Bai、Lulu Zhao、Fang Wang、Fachao Yan、Taichi Kano、Keiji Maruoka、Yuehui Li
DOI:10.1021/acs.orglett.0c01812
日期:2020.7.17
straightforward method to synthesize chiral pyrrolo[1,2-a]indole bearing a tetrasubstituted carbon stereocenter. The reaction proceeds smoothly with a wide array of substrate tolerance to deliver various chiral pyrrolo[1,2-a]indoles in up to 93% yield and 98% ee. The utility of this method is highlighted by the diverse transformations of the products into various indolederivatives.
我们报道了手性磷酸催化的3-取代的1 H-吲哚和含有功能性导向基团(对-NHAc或对-OH)的炔丙醇的正式(3 + 2)环加成反应。这项工作代表了一种简单的方法来合成带有四取代碳立体中心的手性吡咯并[1,2- a ]吲哚。反应以多种底物耐受性顺利进行,以高达93%的收率和98%ee的产率递送各种手性吡咯并[1,2- a ]吲哚。通过将产物多样化转化为各种吲哚衍生物,突出了该方法的实用性。
para-Toluenesulfonic Acid Catalyzed Synthesis of Indenes via a Tandem Friedel–Crafts Alkylation/Hydroarylation of Tertiary Propargylic Alcohols with Electron-Rich Arenes
A simple protocol to synthesize indenes efficiently by PTSA catalyzed tandem Friedel–Crafts alkylation/hydroarylation of tertiary propargylic alcohol with electron-rich arenes is described. The desired indenes were obtained regioselectively in good to very good yields under mild reaction conditions. The allene intermediate was isolated to get an insight into the mechanistic pathway of the indene forming