Cross-coupling is a chemical reaction that allows the joining of two different molecules, typically involving organic compounds. This process often uses a catalyst, which is a substance that speeds up the reaction without being consumed. Cross-coupling is widely used in organic synthesis to create complex molecules, making it essential in fields like pharmaceuticals and materials science. One of the most common types of cross-coupling reactions is the Suzuki reaction, which connects aryl halides with boronic acids. Other notable methods include the Heck reaction and the Stille reaction. These techniques enable chemists to build diverse and functionalized compounds efficiently.