Cross Coupling

A cross-coupling reaction in organic synthesis occurs when two fragments are joined together with the aid of a metal catalyst. Cross-coupling has been an essential reaction in catalytic chemistry for the past 30 years starting with the pioneering work by Heck, Negishi, and Suzuki, who were awarded the Nobel Prize in Chemistry in 2010 for palladium-catalyzed cross-coupling. As one of the most versatile and powerful bond-forming methods in synthetic organic chemistry, the field of cross-coupling has matured to the point where nearly any two fragments can be coupled with the right catalyst. With its usage increasing exponentially, the field has grown to include numerous strategies for carbon-carbon, carbon-nitrogen, and carbon-oxygen bond formation, including key reactions such as:

• Negishi coupling is the cross-coupling of an aryl (pseudo)halide and an organozinc nucleophile to form C-C bonds.
• Suzuki-Miyaura coupling, the cross-coupling of an aryl (pseudo)halide and organoborate, is a versatile reaction for carbon-carbon bond formation.
• Stille coupling, the cross coupling of an aryl (pseudo)halide and stannanes, is a functional reaction for carbon-carbon bond formation with few limitations on the R-groups.
• Heck coupling is the cross coupling of an unsaturated halide with an alkene to give substituted alkenes.
• Sonogashira coupling is the cross-coupling of an aryl (pseudo) halide with a terminal alkyne to give disubstituted acetylenes.
• Buchwald-Hartwig amination, the cross-coupling of an aryl (pseudo)halide and an amine, is a staple reaction for chemists across a wide range of disciplines.