Metal-Free Oxidative Cross-Coupling Reaction of Thiophene Iodonium Salts with Pyrroles
作者:Koji Morimoto、Akira Nakamura、Toshifumi Dohi、Yasuyuki Kita
DOI:10.1002/ejoc.201600791
日期:2016.9
The hypervalent-iodine-mediated oxidative metal-free cross-coupling reaction of thiophenes with various pyrroles was developed. The corresponding thiophene–pyrrole derivatives were obtained in moderate to high yields (up to 85 %). This method features high efficiency and regioselectivity and broad functional group tolerance. We further determined the highly planar characteristics of the 3,4-ethyle
A heterocycle-containing aromatic compound represented by the formula: A-B, and an electrically conductive polymer obtained by oxidative polymerization of the heterocycle-containing aromatic compound as a monomer are provided. In the above formula, A represents a substituted or unsubstituted thiophene ring group, or a substituted or unsubstituted pyrrole ring group; B represents a substituted or unsubstituted hydrocarbon aromatic ring group, a substituted or unsubstituted thiophene ring group, or a substituted or unsubstituted pyrrole ring group; the ring represented by A and the ring represented by B are directly linked; however, A and B represent structures that are different from each other. The compound can be produced by a coupling reaction using a hypervalent iodine reactant.
A new strategy for mixed biaryl synthesis has been developed using the hypervalent iodine(III) reagents. The unique reactivities of the sigma-heteroaryl iodine(III) intermediates generated in situ are the key element for the unusual metal catalyst-free transformations and strict control of the product selectivities.
Application of a DIB/BBr<sub>3</sub> protocol in metal-free aryl coupling reactions
Metal-free direct C–H functionalization reactions are a promising approach to convert hydrocarbon feedstock into value-added molecules. Diacetoxyl iodobenzene (DIB) is a benchtop stable hypervalent iodine compound that is frequently used as a non-metal oxidant in C–H functionalization. However, DIB has a relatively low reactivity and an acid promoter is usually required to achieve satisfactory performance