Highly Selective and Atom Economical Synthesis of 1,3-Enynes, Pyrroles and Furans by Manganese(I)-Catalyzed C–H Activation

A highly selective Mn(I)-catalyzed alkenylation of arenes and heteroarenes with 1,3-diynes is described. The reported transformation overcomes regio-, chemo- and stereoselectivity challenges associated with the use of these coupling partners. Both symmetrical and unsymmetrical diynes can be applied in this protocol, affording single isomers not only in the synthesis of 1,3-enynes but also in the one-step preparation of pyrroles and furans. This simple and highly atom economical strategy features wide functional group tolerance, good reproducibility and preparative scale utility. The manganese catalyst plays a crucial role in this C−H activation protocol, enabling high selectivity with previously challenging internal alkynes. Furthermore, the synthetic value of the method is highlighted by diverse post-functionalizations of the final products.