phenylzinc

Phenylzinc refers to a class of organozinc compounds that contain a phenyl group bonded to zinc. The term covers phenylzinc halides such as phenylzinc chloride (PhZnCl) and higher-order species such as diphenylzinc (Ph2Zn) and phenylzinc bromide (PhZnBr). These reagents are part of the broader family of organozinc compounds used as carbon nucleophiles in organic synthesis.

Preparation and properties: Phenylzinc reagents are typically prepared by transmetalation of aryl Grignard reagents (ArMgX) with zinc salts (for example ZnCl2) to give arylzinc chlorides (ArZnCl), which can be isolated or used in situ in dry solvents such as THF. Alternative routes include transmetallation from organolithium reagents. Organozinc compounds generally exhibit greater air and moisture tolerance than Grignard reagents, but they are still handled under inert atmosphere in dry solvents to maintain reactivity.

Reactivity and applications: A defining feature of phenylzinc reagents is their milder reactivity compared with organolithium or Grignard reagents, making them compatible with a broader set of functional groups. They are widely employed as nucleophiles in transition-metal-catalyzed cross-coupling reactions, especially Negishi coupling, where phenylzinc reagents couple with aryl, vinyl, or alkyl halides under palladium or nickel catalysis to form biaryl and related products. They can also participate in other zinc-mediated transformations and serve as building blocks for the construction of complex phenyl-containing molecules.

Safety and handling: Phenylzinc compounds are typically air- and moisture-sensitive and are used under inert atmosphere. They are usually prepared and deployed as solutions in dry solvents and handled with standard organozinc precautions. See also organozinc chemistry for related reagents and cross-coupling methodologies.