A general protocol for cross-coupling reactions can be made using nickel salt and visible light, according to a paper in Nature.

A cross-coupling reaction is the coupling of C atoms having a double bond [C(sp2)] to other atoms and usually occurs with transition metals. Well-known examples are the Suzuki-Miyaura coupling, the Heck reaction and the Negishi coupling. With all these different reactions you have a lot of possibilities, but the disadvantage is that the reaction conditions vary just as much. A Russian-German team has now developed a method that makes it much easier to perform different couplings, which should save a lot of optimisation steps.