Trifluoromethyl aryl diazirines are ubiquitous in chemical biology applications, and are increasingly used in materials science. While the electron‐withdrawing α ‐CF 3 group is known to stabilize the carbene resulting from diazirine activation, no alternative electron‐withdrawing groups have been systematically studied. Here, we describe the synthesis of the first α ‐ester aryl diazirines and show that they activate at lower temperatures than their trifluoromethyl‐containing analogs, while still permitting tunable activation and good efficiency in CH insertion reactions. We anticipate the use of α ‐ester aryl diazirines in materials science applications (due to their high insertion yield with a nonfunctionalized aliphatic model substrate) and biological wound healing (due to their ability to be thermally activated at < 37°C).
Andersen et al. (Fri,) studied this question.