474079-06-6Relevant academic research and scientific papers
β-Nitroacrylates as Starting Materials of Thiophene-2-Carboxylates Under Continuous Flow Conditions
Chiurchiù, Elena,Patehebieke, Yeersen,Gabrielli, Serena,Ballini, Roberto,Palmieri, Alessandro
, p. 2042 - 2047 (2019)
We report herein a general and efficient continuous flow-based protocol for synthesizing thiophene-2-carboxylates starting from ketal-functionalized β-nitroacrylates. The protocol involves (i) a promoter-free conjugate addition of thioacetic acid to β-nitroacrylates, (ii) a base-induced elimination of nitrous acid, and (iii) a final acid-promoted domino cyclization-aromatization process to afford the title targets. Thanks to the means of the flow chemistry and the use of solid supported systems, the three steps were combined in a whole flow chemical process, by which the products were isolated in good to excellent overall yields (38–88%). (Figure presented.).
