A new iridium catalyst forces chemical bonds to form in the wrong place, breaking a rule that has governed organic chemistry for a century.
This catalyst overrides the standard electronic preference in Michael addition reactions, a cornerstone of molecular synthesis. It pushes bonds to form at the alpha-position of an alkene when they should naturally go to the beta-position. This breakthrough allows chemists to build molecules that were previously thought to be impossible or incredibly expensive to make. It effectively rewrites the playbook for building complex medicines and advanced materials. This discovery proves that even the most fundamental laws of chemistry can be bypassed with the right catalyst.
An Iridium Catalyst Switches the Regioselectivity of Michael Addition Reactions
ChemRxiv · 10.26434/chemrxiv.15002845/v1
The Michael reaction is a cornerstone transformation in organic synthesis. Its regioselectivity is governed by electronic control, and this enforces C–C bond formation exclusively at the βposition of electron-poor alkenes. Here, we report an iridium-catalyzed approach that instead enables unprecedented α-selective “anti-Michael” C(sp3)–H additions to acrylates and other conjugate acceptors. Our strategy is predicated on the use of directing groups to promote the formation of chelated Ir-(aza)-en