Word Count : 1054

---

The Negishi coupling reaction is an important transition-metal-catalysed cross-coupling reaction used in Organic Chemistry for the formation of carbon–carbon bonds. It involves the coupling of an organic halide or pseudohalide with an organozinc compound in the presence of a transition-metal catalyst, generally palladium or nickel. The reaction was developed by Ei-ichi Negishi and has become a valuable method for the synthesis of biaryls, substituted alkenes, alkylated aromatic compounds and other structurally complex organic molecules. The general reaction can be represented as: [ R-X + R'-ZnX' \xrightarrow[\text{ligand}]{Pd\ or\ Ni} R-R' ] Here, (R-X) represents an aryl, vinyl or alkyl halide, while (R'-ZnX') represents an organozinc reagent. (X) is generally Cl, Br or I. The organozinc reagent may contain alkyl, alkenyl, aryl or other carbon groups. The important feature of the Negishi reaction is that the carbon group attached to zinc is transferred to the organic halide through the action of a palladium or nickel catalyst. For example, ethylbenzene can be prepared by coupling bromobenzene with ethylzinc chloride: [ C_6H_5Br + C_2H_5ZnCl \xrightarrow{Pd(PPh_3)_4} C_6H_5C_2H_5 + ZnBrCl ] In this reaction, bromobenzene acts as the organic halide and ethylzinc chloride acts as the organozinc reagent. Tetrakis(triphenylphosphine)palladium(0), (Pd(PPh_3)_4), may be used as the catalyst. The phenyl group originally bonded to bromine becomes bonded to _________ ______ ____ ________ _____ _________ _______ ____ ________ __________.
______ _________ _____ __________ ___ ________ ____ ________ _____ _______ ____ __________.
______ ______ ___ ________ ___ ________ __________ _______ _________ ________ _____ _____.
____ _________ ____ ___ _________.
_________ ____ ______ _______ ________ ___ _______ ____ _________ ___ ______ _________.
________ ________ _______ __________ ________ ______.
_______ _________ __________ _______ __________ _______ _______ ___ _______ ___ __________.
__________ _______ ________ ______ _________ _______ ________ __________ ____.
_______ ____ _____ _________ ______ _____ __________ ____ ________ ___.
_______ ____ ________ ______ ___.
______ _______ ___ __________ ____.
________ __________ ___ ____ ___ ___ ________ _________.
____ ____ _________ _________ __________ _________ _________ ____.
_________ ____ ________ _________ ___ _____ ____ _______ __________.
____ _____ ______ _____ ________ ________ __________ ________ _______ _________.
__________ __________ _________ ____ ________ ____ _______ _______ _____ __________ __________.
___ ________ ___ _______ ______ _______ _________ _____ _______ _______ ________ _________.
__________ _______ __________ _________ ________ ___ _________ ___ __________ _____ _________ ___.
____ __________ _______ ________ ___ _________ _________ ___ _________ ________ _________ _________.
_______ ________ ___ _____ _______ ___ __________ ____ ________ _______.
___ _____ ____ ___ _______ ___ _______ ___ _____ _______ _________ _________.
________ ______ _________ _________ _________ ____ ___ ___ _________ _________ _____.
_________ _____ _______ _______ _______.
________ ____ ______ ________ ____ _______.
____ _____ ________ ____ _____ ____ _____ _____ _____ _________.
_________ ___ _____ ________ _______.
_____ __________ ___ __________ _________ ____ _______ _____ ________ ____ _________ _________.
_________ ______ ___ _____ ________.
_________ _______ ____ ________ ___.
________ _______ _____ _____ _______ _______ _________.
_________ __________ _____ ______ ___ _______.
_______ _________ _________ _____ ________ ________.
_______ _________ _________ ____ _____.
________ _____ ______ _________ ______ ________ ________ ____ ___ _____.
____ _________ _____ _______ ____ ______ _________ ________ ________ _______.
________ ___ __________ ______ ______ ____ _______ _____ _______ _______.
______ ____ ____ _________ _____ ________ ___ ____ ________ ___.
___ ___ ___ __________ _________ ________ _________ ____ ______ __________ _______ _________.
________ ________ ___ ___ _________ __________ ______.
_______ _____ _____ _________ ________ _______ _________ _______ _________ _________.
______ _______ ______ ____ _______ ________ ____.
_____ ___ __________ __________ ____ ________ __________ ____ _____.
____ __________ _______ ______ _____ ____ _________ _________.
____ ______ ___ ___ ____ _____ _______ ______ _____ _______ ______.
_________ _________ ______ ____ _______ ______ _____ ______.
_____ _________ ______ _____ ___ _________ _____ ______ ___ ______ __________.
_______ ________ _________ ________ ___.
_____ ______ ______ _________ ______ ___ _____.
___ ___ _________ ___ ___.
___ __________ ______ _________ ______.
__________ _________ ____ _____ ______ _________ ___ _________.
_____ ________ ___ ____ ________ _______.
____ _________ _______ ___ ______ ____.
______ __________ ______ _________ _________.
________ __________ _____ __________ ___ ___ __________ _____ _____ ______ ______ ______.
______ _________ ___ ________ ______ ________ __________ ________ _______ _______ _________.
_________ ____ ________ ____ _________ ____ _____ ___ _____ _________ ___ ______.
________ __________ ___ _______ _____ ___ _______ ___ _______.
_____ ___ ________ _______ ________.
______ _________ __________ _________ ___ ______ _____ ___ ________ ______ ____ ________.
__________ ______ ________ _____ _______ _____ ____ ________ __________ _________ _____ ________.
________ _____ ________ ________ _____ ______ ______.
_____ ______ ____ ___ ____ ____ _____ _________ _______ ______.
_________ ________ _______ ___ ___ _______ ___ __________ _____ __________ ______ ___.
________ __________ ____ ______ ___ _______ ___ ______ ________ ___.
______ ___ ______ ______ ____ __________ ____ ________ _____ ________.
_______ _____ ____ _______ ________ _____ _________ ________ ___ __________.
_____ _______ ________ _____ ______ _________.
______ ________ ________ ____ ________ ________ _____ ________ __________ _______ ____ ____.
________ ____ _______ _____ _____ _____.
_______ _________ _______ ___ ______ _________ ______ ______ _____.
_________ ________ _____ _________ ____ _______ _____ ____ _________ ___.
____ _______ _____ ___ _________.
__________ _________ ___ ______ ____ ______ __________ ___ _____ _____ ___.
______ _________ ________ _________ ______.
______ _____ ________ ___ ______.
_______ _______ ___ ____ _____ ______ ___ _________ ______ ____ _____ ____.
______ _______ ___ _______ __________ ____ _____ _________.
______ ___ _________ _________ ________.
____ ___ ___ _______ ________ ___ _____.
____ _______ ______ ____ _____ ________ _________ _____ ___ _________ ____ ______.
______ _________ _________ __________ ___ _______.
___ _________ _______ _________ _______ _____ ______.
_________ __________ ________ _____ _________ ______ _____ ______ ___ ________.
____ ___ __________ ___ __________ _____.
______ ____ ____ _________ ______ _____ ____ ________.
_______ ___ _________ ______ ________ ________ _____ _______ ______ __________ ________ __________.
_____ ____ ________ __________ ____ ______ ______ ___ ____ _______ _____.
_________ ___ _______ ____ _______ ___ ______ __________ _____.
___ ________ _______ _____ _____ _______ ____ ______ _______ _________.
_______ __________ ________ ___ ______ ___.
______ _____ _________ _________ _____ ________ _________ ________ ___.
____ _______ ___ _________ ____ _____ __________ __________ ______ ____ ____ __________.
_________ _______ ________ ________ __________ __________ ________ ____ _________ __________ _____ _____.
_________ ______ ____ __________ _______ _____ ________ __________ _________ __________.
_______ _____ ________ ______ _______ _____.
___ _______ _____ _____ ________ _______ ______ _____ ______ _______.
_____.
Get Full Answer on WhatsApp