Catalytic 1,4-Rhodium(III) Migration Enables 1,3-Enynes to Function as One-Carbon Oxidative Annulation Partners in CH Functionalizations
作者:David J. Burns、Hon Wai Lam
DOI:10.1002/anie.201406072
日期:2014.9.8
1,3‐Enynes containing allylic hydrogens cis to the alkyne are shown to act as one‐carbon partners, rather than two‐carbon partners, in various rhodium‐catalyzedoxidativeannulations. The mechanism of these unexpected transformations is proposed to occur through double CH activation, involving a hitherto rare example of the 1,4‐migration of a RhIII species. This phenomenon is general across a variety
Functionalization of C sp 3H and C sp 2H Bonds: Synthesis of Spiroindenes by Enolate-Directed Ruthenium-Catalyzed Oxidative Annulation of Alkynes with 2-Aryl-1,3-dicarbonyl Compounds
作者:Suresh Reddy Chidipudi、Imtiaz Khan、Hon Wai Lam
DOI:10.1002/anie.201207170
日期:2012.11.26
Ru(de) awakening: The synthesis of carbocycles by the ruthenium‐catalyzedoxidativeannulation of alkynes with 2‐aryl cyclic 1,3‐dicarbonyl substrates is described. Proceeding by the functionalization of CH and CH bonds, and the formation of an all‐carbon quaternary center, the reaction provides a diverse range of spiroindenes in good yields with high levels of regioselectivity.
Photoredox‐Catalyzed Isomerization of Highly Substituted Allylic Alcohols by C−H Bond Activation
作者:Kai Guo、Zhongchao Zhang、Anding Li、Yuanhe Li、Jun Huang、Zhen Yang
DOI:10.1002/anie.202000743
日期:2020.7.6
Photoredox‐catalyzed isomerization of γ‐carbonyl‐substituted allylicalcohols to their corresponding carbonyl compounds was achieved for the first time by C−H bond activation. This catalytic redox‐neutral process resulted in the synthesis of 1,4‐dicarbonyl compounds. Notably, allylicalcohols bearing tetrasubstituted olefins can also be transformed into their corresponding carbonyl compounds. Density
developed under redox-neutral ruthenium(II) catalysis, offering a wide variety of valuable 3-aryl succinimides including amino acid embedded frameworks in good to excellent yields. The products were also aromatized to produce synthetically useful resorcinol-based biaryls. Mechanistic studies support an organometallic pathway with a reversible C–H metalation step for this reaction.
在氧化还原中性钌 (II) 催化下开发了一种烯醇辅助的区域选择性芳烃 C-H 与马来酰亚胺的烷基化反应,提供了多种有价值的 3-芳基琥珀酰亚胺,包括氨基酸嵌入框架,收率良好至极佳。产物也被芳构化以产生合成有用的基于间苯二酚的联芳基化合物。机理研究支持有机金属途径与该反应的可逆 C-H 金属化步骤。
Synthesis of Benzopyrans by Pd(II)- or Ru(II)-Catalyzed C–H Alkenylation of 2-Aryl-3-hydroxy-2-cyclohexenones
作者:Suresh Reddy Chidipudi、Martin D. Wieczysty、Imtiaz Khan、Hon Wai Lam
DOI:10.1021/ol3033835
日期:2013.2.1
2-Aryl-3-hydroxy-2-cyclohexenones are shown to be competent substrates for palladium- and ruthenium-catalyzed C-H alkenylation reactions with terminal alkenes, providing, in most cases, benzopyrans.