Enantioselective Palladium‐Catalyzed Hydrophosphinylation of Allenes with Phosphine Oxides: Access to Chiral Allylic Phosphine Oxides
作者:Zhiping Yang、Jun (Joelle) Wang
DOI:10.1002/anie.202112285
日期:2021.12.20
A highly efficient, versatile and atom-economic protocol to chiral allylic phosphineoxides is demonstrated via palladium-catalyzed asymmetric hydrophosphinylation of allenes with phosphineoxides. A family of chiral allylic phosphineoxides with a diverse range of functional groups were obtained in high yield (up to 99 %) and enantioselectivities (up to 99 % ee).
A palladium-catalyzed four-component cascade reaction of carbon dioxide, amines, allenyl ethers, and aryl iodides has been developed for the first time. The novel reaction allows simultaneous construction of three different new bonds (C–N, C–O, and C–C) in a single step, affording an efficient method for the synthesis of a variety of highly functionalized acyclic O,O-acetals. Excellent chemo- and regioselectivity
Gold(I)-Catalyzed Enantioselective Annulations between Allenes and Alkene-Tethered Oxime Ethers: A Straight Entry to Highly Substituted Piperidines and <i>aza</i>-Bridged Medium-Sized Carbocycles
作者:David C. Marcote、Iván Varela、Jaime Fernández-Casado、José L. Mascareñas、Fernando López
DOI:10.1021/jacs.8b10388
日期:2018.12.5
present in a wide range of bioactive natural products and are therefore considered as highly valuable, privileged synthetic targets. In this manuscript, we describe a gold-catalyzed annulation strategy that allows a straightforward assembly of piperidines and piperidine-containing aza-bridged productsfrom readily available alkene-tethered oximeethers (or esters) and N-allenamides. Importantly, we
Pauson–Khand reactions of functionalized allenes with different alkynes give cyclopentenones with generally high regio- and stereoselectivities. The allenes react through their external double bonds, giving cyclopentenones with exocyclic double bond at their β positions and predominantly with E stereochemistry. Some intramolecularreactions with allenynes connected through aromatic rings are described
具有不同炔烃的官能化丙二烯的 Pauson-Khand 反应产生具有通常高区域选择性和立体选择性的环戊烯酮。丙二烯通过它们的外部双键反应,得到在其 β 位置具有环外双键的环戊烯酮,主要是 E 立体化学。描述了通过芳环连接的丙炔的一些分子内反应。这些以中等至良好的产率得到相应的杂环。