TY - JOUR
T1 - Reactivity of substituted benzenes toward oxidative addition relates to NMR chemical shift of the ipso-carbon
AU - Coperet, Christophe
AU - Gordon, Christopher P.
AU - Kashihara, Myuto
N1 - Funding Information:
M.K. acknowledges the Mazume Research Encouragement Prize from Kyoto University for financial support. C.P.G. thanks the Scholarship Fund of the Swiss Chemical Industry (SSCI) for funding. This work is dedicated to Prof. E. Negishi on the occasion of his 85th birthday.
Publisher Copyright:
© 2020 American Chemical Society
PY - 2020/11/20
Y1 - 2020/11/20
N2 - The oxidative addition of benzene derivatives to Pd0 catalysts is a key step in cross-coupling reactions. In this work, we show that the ipso-carbon chemical shift of substituted benzenes, and in particular the δ22 component of the chemical shift tensor, correlates with the free energy barrier for oxidative addition. This correlation is traced back to the electron density in the pz orbital of the ipso-carbon (perpendicular of the ring-plane), with high electron densities favoring oxidative addition. The correlation between chemical shift and free energy barrier holds true for a variety of substituted benzenes, making chemical shift a useful descriptor for predicting the reactivity of aromatic substrates in oxidative addition.
AB - The oxidative addition of benzene derivatives to Pd0 catalysts is a key step in cross-coupling reactions. In this work, we show that the ipso-carbon chemical shift of substituted benzenes, and in particular the δ22 component of the chemical shift tensor, correlates with the free energy barrier for oxidative addition. This correlation is traced back to the electron density in the pz orbital of the ipso-carbon (perpendicular of the ring-plane), with high electron densities favoring oxidative addition. The correlation between chemical shift and free energy barrier holds true for a variety of substituted benzenes, making chemical shift a useful descriptor for predicting the reactivity of aromatic substrates in oxidative addition.
UR - http://www.scopus.com/inward/record.url?scp=85096508684&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85096508684&partnerID=8YFLogxK
U2 - 10.1021/acs.orglett.0c03300
DO - 10.1021/acs.orglett.0c03300
M3 - Article
C2 - 33147975
AN - SCOPUS:85096508684
SN - 1523-7060
VL - 22
SP - 8910
EP - 8915
JO - Organic Letters
JF - Organic Letters
IS - 22
ER -