The Aubé group, recently of UNC, wondered whether expensive setups from scientific vendors were potential roadblocks to wide adoption of electrochemistry. Their ideal recipe called for a direct current (DC) source capable of removing two electrons and an H from a lactam to generate an N-acyliminium ion. Looking around, the researchers realized that today's ubiquitous cellphone chargers might just do the trick. Shave back some wires, attach some copper clamps, and presto! Cheap, effective electrochemistry.**
Using their DIY e-chem setup, the Aubé group traps a wide variety of stereochemically-rich acyliminiums as the corresponding methanol adducts (19-93% yields). Now the real fun starts: there's a whole bunch of interesting arylations and other additions to these species one can access using off-the-shelf Lewis acids like titanium tetrachloride or boron trifluoride:
|Adapted from Aube, Angewandte Chemie, 2015 ASAP|
I'll be excited to see small libraries of diversified products emerge from this work. However, a "one-pot" functionalization - electrochemistry with the desired nucleophile already present - still seems a distant dream.
Hopefully, the apparent ease of operation of "cellphone charger e-chem" prompts other groups to give it a try. If your group dips their toes into this field, please drop me a line in the comments section.
*Thanks to Professor Brandon Findlay (@Chemtips) for pointing out this paper!
**I'm tickled pink at how many organic synthesis papers these days include photographic records of reaction setups. I'd like to believe that Blog Syn played a small role in advancing this change.