Manganese(I)-Catalyzed Substitutive C−H Allylation

The first manganese(I)‐catalyzed C−H allylations with ample scope were achieved by carboxylate assistance. The highly selective C−H/C−O functionalizations proved viable with densely substituted allyl carbonates, and the organometallic C−H allylation strategy set the stage for expedient late‐stage diversification with excellent levels of positional selectivity. Manganese(I) carboxylate catalysts allow step‐economical C−H allylations with broad substrate scope. The reaction proceeds through redox‐neutral organometallic C(sp2)−H activation, which has the advantage of enabling the transformative late‐stage diversification of functionalized molecules.