Abstract: Hydrofunctionalizations are an attractive method for functionalizing olefins, forging new bonds in an atom-economic and sustainable fashion. We developed a variety of Rh–H catalysts that can couple heteroatom nucleophiles with olefin coupling partners.. In the first example, we developed an intermolecular anti-Markovnikov hydroamination of 1,3-dienes to form homoallylic amines. In the second example, we developed a divergent hydrothiolation of cyclopropenes. Depending on the choice of bisphosphine ligand on the Rh–H catalyst, either direct hydrothiolation occurs to from cyclopropyl sulfide products, or ring-opening of the cyclopropenes occurs to form allylic sulfide products. Choice of bisphosphine ligands for the Rh catalysts is important for achieving selectivity when the hydrofunctionalization has many potential outcomes.
Another way to form Rh–H intermediates is through the activation of aldehyde C–H bonds by a Rh catalyst. An oxidative-dehydroformylation cascade to dehomologate primary alcohols to olefins is enabled by the addition of N,N-dimethylacrylamide as a hydrogen acceptor. In addition, our lab previously developed a dynamic kinetic resolution of aldehydes through intramolecular hydroacylation, where a bulky primary amine co-catalyst was used to selectively racemize the aldehyde starting material. By further activating the Rh catalyst through hydrogenation and employing acrylamides as the coupling partner, we extend this dynamic kinetic resolution of aldehydes through intermolecular hydroacylation.