R. Sakakibara, Kennosuke Itoh, H. Fujii
Jul 16, 2019
Citations
0
Influential Citations
4
Citations
Journal
The Journal of organic chemistry
Abstract
Ligand-dependent Suzuki cross-coupling of 4-bromopyrazol-5-yl triflates has been developed. This approach enabled selective introduction of an aryl substituent at the C4 or C5 position in the pyrazoles. This protocol is the first example in which the cross-coupling proceeded predominantly at the C4 position in pyrazoles, which is generally recognized as the least reactive position. The selection of phosphine ligands switched the order of the arylation. This method should be highly useful for preparing diverse poly-substituted pyrazole derivatives.