Visible-Light Photoredox-Catalyzed Decarboxylative Alkylation of Heteroarenes Using Carboxylic Acids with Hydrogen Release
作者:Wan-Fa Tian、Chun-Hong Hu、Ke-Han He、Xiao-Ya He、Yang Li
DOI:10.1021/acs.orglett.9b02539
日期:2019.9.6
Herein, we have developed visible-lightphotoredox-catalyzed decarboxylating carboxylic acids for alkylation of heteroarenes under mild conditions. The transformation occurred smoothly without the requirement of stoichiometric oxidants in the presence of 0.3 equiv of base, which benefited from the release of hydrogen (H2) and carbon dioxide (CO2). Various substrates and functional groups were tolerated
Long‐ing alkyl chain: The catalytic direct CH alkylation of azoles with unactivatedalkyl bromides and chlorides is described. A palladium catalyst enables the alkylation of oxazoles, whereas a nickel one shows unique activity for thiazole. The catalyses allow a straightforward access to azole motifs bearing long, functional alkyl side chains.
Iron-Catalyzed C–H Alkylation of Heterocyclic C–H Bonds
作者:Kaki Raveendra Babu、Nengbo Zhu、Hongli Bao
DOI:10.1021/acs.orglett.6b03287
日期:2017.1.6
An efficient, iron-catalyzed C–H alkylation of benzothiazoles by using alkyl diacyl peroxides and alkyl tert-butyl peresters which are readily accessible from carboxylic acids to synthesize 2-alkylbenzothiazoles is developed. This reaction is environmentally benign and compatible with a broad range of functional groups. Various primary, secondary, and tertiary alkyl groups can be efficiently incorporated
Functionalized Orthoesters as Powerful Building Blocks for the Efficient Preparation of Heteroaromatic Bicycles
作者:Gulluzar Bastug、Christophe Eviolitte、István E. Markó
DOI:10.1021/ol301472a
日期:2012.7.6
By combining substituted anilines with functionalized orthoesters, an efficient and connective methodology for the preparation of benzoxazole, benzothiazole, and benzimidazole derivatives has been established. The versatility of this approach enables the development of new libraries of heterocycles containing multifunctional sites.
Ni-Catalyzed Reductive Liebeskind–Srogl Alkylation of Heterocycles
作者:Yuanhong Ma、Jose Cammarata、Josep Cornella
DOI:10.1021/jacs.8b13534
日期:2019.2.6
Herein we present a Ni-catalyzed alkylation of C–SMe with alkyl bromides for the decoration of heterocyclic frameworks. The protocol, reminiscent to the Liebeskind–Srogl coupling, makes use of simple C(sp2)–SMe to be engaged in a reductive coupling. The reaction is suitable for a preponderance of highly valuable heterocyclic motifs. In addition to cyclic bromides, noncyclic alkyl bromides are well
在此,我们提出了用烷基溴对 C-SMe 进行 Ni 催化烷基化,用于装饰杂环骨架。该协议让人想起 Liebeskind-Srogl 耦合,利用简单的 C(sp2)-SMe 进行还原耦合。该反应适用于占优势的高价值杂环基序。除了环溴化物外,非环烷基溴化物也能很好地适应异构化的保留水平。该协议是可扩展的,并允许在存在其他功能化句柄的情况下进行正交耦合。