β‐Nitroacrylates as Starting Materials of Thiophene‐2‐Carboxylates Under Continuous Flow Conditions

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%).