[reaction: see text] The first asymmetric aminolysis of trans-aromatic epoxides with anilines is described. The process affords enantioenriched anti-beta-amino alcohols in up to 99% ee. The complete regio- and diastereoselectivity observed uses commercially available [Cr(Salen)Cl] as a Lewis acid catalyst and in combination with a very simple experimental procedure renders the present reaction a facile
Palladium-Promoted Neutral 1,4-Brook Rearrangement/Intramolecular Allylic Cyclization Cascade Reaction: A Strategy for the Construction of Vinyl Cyclobutanols
作者:Hao Zhang、Shiqiang Ma、Ziyun Yuan、Peng Chen、Xingang Xie、Xiaolei Wang、Xuegong She
DOI:10.1021/acs.orglett.7b01381
日期:2017.7.7
cascade reaction to build vinyl cyclobutanol rings through activation of vinyl epoxides by palladium, followed by 1,4-Brook rearrangement and intramolecular cyclization with a palladium complex of the resulting carbon anion, is described. Through this cascade reaction, several highly substituted cyclobutanol substrates were achieved in good yields with high stereoselectivities.
A simple and mild procedure has been developed for the first time for the C-3selective ring-opening of aromatic 2,3-epoxy alcohols/epoxides with aromatic amines catalysed by (3-cyclodextrin in water at room temperature to afford the corresponding β-aminoalcohols in excellent yields with high regioselectivity.
Asymmetric Synthesis of Dihydroindanes by Convergent Alkoxide-Directed Metallacycle-Mediated Bond Formation
作者:Stephen N. Greszler、Holly A. Reichard、Glenn C. Micalizio
DOI:10.1021/ja2105043
日期:2012.2.8
A convergent synthesis of highlysubstituted and stereodefined dihydroindanes is described from alkoxide-directed Ti-mediated cross-coupling of internal alkynes with substituted 4-hydroxy-1,6-enynes (substrates that derive from 2-directional functionalization of readily available epoxy alcohol derivatives). In addition to describing a new and highly stereoselective approach to bimolecular [2 + 2 +
Palladium-Catalyzed Formation of Substituted Tetrahydropyrans: Mechanistic Insights and Structural Revision of Natural Products
作者:Ronaldo Pilli、Franco Della-Felice、Francisco de Assis、Ariel Sarotti
DOI:10.1055/s-0037-1611708
日期:2019.4
cryptoconcatone H. Experimental and computational DP4+ NMR results were used to assess the structures proposed for cryptoconcatones K and L. A comprehensive study on the stereochemical outcome of palladium-catalyzed formation of 2,4,6-trisubstitutedtetrahydropyrans through cyclization of the corresponding allylic acetates using both Pd(0) and Pd(II) catalysts is presented. We have found that the stereochemical
这项工作是献给Albert J. Kascheres教授的指导和对我们当中一个人的积极榜样(RAP)。 抽象的 提出了对钯催化通过使用Pd(0)和Pd(II)催化相应的烯丙基乙酸酯环化形成2,4,6-三取代四氢吡喃的立体化学结果的全面研究。我们已经发现,这种环化的立体化学结果不仅取决于无环前体的立体化学,而且还取决于钯催化剂的性质。这些结果被用于隐孢子酮H推定结构的全合成。实验和计算的DP4 + NMR结果被用于评估拟隐孢子酮K和L的结构。 提出了对钯催化通过使用Pd(0)和Pd(II)催化相应的烯丙基乙酸酯环化形成2,4,6-三取代四氢吡喃的立体化学结果的全面研究。我们已经发现,这种环化的立体化学结果不仅取决于无环前体的立体化学,而且还取决于钯催化剂的性质。这些结果被用于隐孢子酮H推定结构的全合成。实验和计算的DP4 + NMR结果被用于评估拟隐孢子酮K和L的结构。