Efficient and Practical Oxidative Bromination and Iodination of Arenes and Heteroarenes with DMSO and Hydrogen Halide: A Mild Protocol for Late-Stage Functionalization
efficient and practical system for inexpensive bromination and iodination of arenes as well as heteroarenes by using readily available dimethyl sulfoxide (DMSO) and HX (X = Br, I) reagents is reported. This mild oxidative system demonstrates a versatile protocol for the synthesis of aryl halides. HX (X = Br, I) are employed as halogenating reagents when combined with DMSO which participates in the present
Inverting Conventional Chemoselectivity in the Sonogashira Coupling Reaction of Polyhalogenated Aryl Triflates with TMS-Arylalkynes
作者:Miao Wang、Chau Ming So
DOI:10.1021/acs.orglett.1c04138
日期:2022.1.21
Sonogashira couplingreaction with excellent chemoselectivity, affording an inversion of the conventional chemoselectivity order of C–Br > C–Cl > C–OTf. This study also provided an efficient approach to the synthesis of polycyclic aromatic hydrocarbons (PAHs) and the natural product analogue trimethyl-selaginellin L by merging of chemoselective Sonogashira and Suzuki–Miyaura couplingreactions.
A novel and efficient transitionmetal-free C–H bond halogenation of indole derivatives has been developed. 3-Halogenated (3-Br, 3-I) indoles are highly regioselectively produced by this protocol. Simple and readily available halide salts (TBAB, KI) are employed as the halogen source. The transitionmetal-free and the mild conditions make this protocol very easy to handle and practical.
A concise synthesis of novel naphtho[a]carbazoles and benzo[c]carbazoles
作者:Rakhi Pathak、Johanna M. Nhlapo、Sameshnee Govender、Joseph P. Michael、Willem A.L. van Otterlo、Charles B. de Koning
DOI:10.1016/j.tet.2006.01.012
日期:2006.3
Starting from simple indole precursors the synthesis of naphtho[a]carbazoles and benzo[c]carbazoles is described. Key steps include the use of the Suzuki–Miyaura reaction to afford 2- or 3-aryl substituted indoles, as well as a potassium t-butoxide and light assisted aromatic ring-forming reaction.
从简单的吲哚前体开始,描述了萘并[ a ]咔唑和苯并[ c ]咔唑的合成。关键步骤包括使用Suzuki-Miyaura反应提供2-或3-芳基取代的吲哚,以及叔丁醇钾和光辅助的芳香环形成反应。