A guideline for the arylation of positions 4 and 5 of thiazole via Pd-catalyzed cross-coupling reactions

The arylation of thiazoles in 4- and 5-position was investigated in detail. Suzuki–Miyaura and Stille cross-coupling reactions were tested using thiazoles either as halide or organometal species. The obtained results were critically compared to develop helpful guidelines for selection of the cross-coupling methodology with the best potential for good and reliable results for a given synthetic problem without the need for tedious optimization of reaction parameters.