Enantioselective Gold(I)-Catalyzed Heterocyclization–Intermolecular Exo [4 + 3]-Cycloaddition Reactions for the Synthesis of Chiral Oxa-Bridged Benzocycloheptanes
The highly exo- and enantioselective gold-catalyzed tandem heterocyclization/[4 + 3] cycloaddition of 2-(1-alkynyl)-2-alken-1-ones and 1,3-diphenylisobenzofuran was implemented by utilizing Ming-Phos, which provides a facile access to chiral seven-membered oxa-bridged rings in 80–98% yield with high exo selectivity (exo/endo up to 50:1) and up to 97% ee.
Gold(I)-Catalyzed Reactions between 2-(1-Alkynyl)-2-alken-1-ones and Vinyldiazo Ketones for Divergent Synthesis of Nonsymmetric Heteroaryl-Substituted Triarylmethanes: <i>N-</i> versus <i>C</i>-Attack Paths
作者:Rahul Dadabhau Kardile、Rai-Shung Liu
DOI:10.1021/acs.orglett.0c02765
日期:2020.11.6
Gold-catalyzed synthesis of nonsymmetrical heteroaryl-substitutedtriarylmethanes using 2-(1-alkynyl)-2-alken-1-ones and vinyldiazo ketones is described. In this catalytic sequence, vinyldiazo ketones attack gold-containing 3-furylbenzyl cations to form the observed C(1)-addition products. We also note that vinyldiazo ketones can be thermally cyclized to yield pyrazole derivatives, which can react
A gold(I)‐catalyzed asymmetric intermolecular tandem [3+3]‐cyclization reaction of 2‐(1‐alkynyl)‐2‐ alken‐1‐ones with nitrones has been developed by using Ming‐Phos as a chiral ligand. This method enables access to the stereodivergent synthesis of highly substituted furo[3,4‐d][1,2]oxazines in excellent efficiency and stereoselectivity (up to 99% yield, 99% ee, >20 : 1 dr).
通过使用Ming-Phos作为手性配体开发了金(I)催化的2-(1-炔基)-2-链烯-1-酮与硝酮的不对称分子间串联[3 + 3]环化反应。该方法能够以优异的效率和立体选择性(高达99%的收率,99%ee,> 20:1 dr)获得高度取代的呋喃[3,4- d ] [1,2]恶嗪的立体发散性合成。
Asymmetric Construction of 2,3-Dihydroisoxazoles via an Organocatalytic Formal [3 + 2] Cycloaddition of Enynes with <i>N</i>-Hydroxylamines
An organocatalyticasymmetricformal [3 + 2] cycloaddition of enynones with N-hydroxylamines has been described. A newly designed multifunctional organocatalyst was found to be highly effective, and the method allowed the synthesis of a variety of 2,3-dihydroisoxazoles in good yields with excellent enantioselectivity.
Gold-Catalyzed Cascade Cyclization and 1,3-Difunctionalization To Access Polysubstituted Furans
作者:Yong Xu、Jiangtao Sun
DOI:10.1021/acs.orglett.0c04090
日期:2021.2.5
Gold-catalyzedcascadecyclization and 1,3-difunctionalization of 2-(1-alkyny)-2-alken-1-ones with N,O-acetals are described, leading to the discovery of novel 1,3-oxyaminomethylation and 1,3-aminomethylamination. Typically, by varying the reaction conditions especially the gold catalysts, these two distinct reaction pathways can be controlled in a selective manner. Moreover, tandem cyclization and