Boron-Built Cyclopropanes

Cyclopropanes, the strained 3-member carbocycles, are found in a diverse array of pharmaceuticals, natural products and agrochemicals. Classically, these rings are built via the well-trodden paths of Simmons-Smith cyclopropanation, Corey-Chaykovsky cyclopropanation or transition-metal catalyzed carbene transfer (if you haven’t seen these, definitely look them up!). Ohmiya (Kyoto U, JP) and Sumida (Kanazawa U, JP) instead form cyclopropanes without any catalyst, just light paired with a special boron reagent. Summary Link to article