Fluoroalkyl‐Substituted Diazomethanes and Their Application in a General Synthesis of Pyrazoles and Pyrazolines

Abstract A novel continuous‐flow approach for the synthesis of fluoroalkyl‐substituted diazomethanes has been developed. Utilizing a cheap, self‐made microreactor fluoroalkyl‐substituted amines were transformed into the corresponding diazomethanes using tert ‐butyl nitrite and acetic acid as catalyst. These diazomethanes were employed in [2+3] cycloaddition reactions with olefins and alkynes, yielding valuable pyrazolines and pyrazoles in good to excellent yields.