Chemistry
The Role of Carbenes in Cyclopropanation Reactions
Quick fact
Carbenes are so reactive that they can insert into C–H bonds and even react with inert gases, yet they are tame enough to be used in complex drug synthesis.
Why this is interesting
You know how a double bond is like a handshake between two carbons? What if we could jam a CH2 group in between them? That's exactly what a carbene does—and the result is a tiny, strained ring with surprising uses.