Negishi

Negishi is a Japanese surname and, in chemistry, most often associated with the Negishi coupling, a cross‑coupling reaction named after Ei-ichi Negishi. The Negishi coupling is a palladium- or nickel-catalyzed reaction between organozinc reagents (R–ZnX) and organic halides or pseudohalides (R′–X), forming new carbon–carbon bonds. It is valued for its functional-group tolerance and has become a standard tool in organic synthesis for assembling complex molecules.

Development and scope

The Negishi coupling was developed in the late 1970s and 1980s by Ei-ichi Negishi. The method typically employs a transition-metal catalyst, commonly palladium with phosphine ligands, in an organic solvent such as THF, and can accommodate a wide range of substrates, including aryl, vinyl, and some alkyl partners. Organozinc reagents are prepared from their zinc salts or via transmetallation from other organometallics, and the reaction can be performed on both small and large scales. The Negishi coupling complements other palladium-catalyzed cross-couplings, such as the Suzuki–Miyaura and Heck reactions, expanding the chemist’s toolkit for building carbon–carbon frameworks.

Notable recognition

Ei-ichi Negishi is a Japanese-American chemist who contributed to the field of cross-coupling chemistry. In 2010, he shared the Nobel Prize in Chemistry with Richard Heck and Akira Suzuki for their development of palladium-catalyzed cross-couplings, including the Negishi coupling.

See also

Cross-coupling reactions; organozinc chemistry.