Premium
Structure–Reactivity Relationships in Negishi Cross‐Coupling Reactions
Author(s) -
Dong ZhiBing,
Manolikakes Georg,
Shi Lei,
Knochel Paul,
Mayr Herbert
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200902132
Subject(s) - negishi coupling , substituent , halide , reagent , chemistry , reactivity (psychology) , coupling reaction , medicinal chemistry , catalysis , organic chemistry , medicine , alternative medicine , pathology
Competition experiments have been performed to determine the relative reactivities of substituted bromobenzenes and of different arylzinc reagents in the [Pd(PPh 3 ) 4 ]‐catalyzed Negishi cross‐coupling reaction in THF at 25 °C. The cross‐coupling reactions are accelerated by electron acceptors in the bromobenzenes, the effect of which increases in the order ortho < meta < para . On the other hand, electron acceptors in the arylzinc halides diminish the reaction rates. Hammett correlations show that substituent variations in the bromobenzenes ( ρ =+2.5) have a larger effect than substituent variations in the arylzinc halides ( ρ =−0.98).