Reactivity of mixed organozinc and mixed organocopper reagents: 10 Comparison of the transferability of the same group in acylation of mixed and homo halozinc diorganocuprates with benzoyl chloride. A kinetic study

Pekel Ö., Erdik E.

Journal of Organometallic Chemistry, cilt.751, ss.644-653, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 751
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.jorganchem.2013.10.030
  • Dergi Adı: Journal of Organometallic Chemistry
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.644-653
  • Anahtar Kelimeler: Mixed diorganocuprates, Acylation kinetics of iodozinc, diorganocuprates, Residual group effect, Third order reactions, ORGANIC GROUP-TRANSFER, ORGANOCUPRATE CLUSTERS, GRIGNARD-REAGENTS, ATE COMPLEXES, ALKYL-HALIDES, LITHIUM, CHEMISTRY, MECHANISM, LIGAND, AMINATION
  • Ankara Üniversitesi Adresli: Evet

Özet

A detailed kinetic study has been carried out for the acylation of iodozinc n-butyl (substituted phenyl) cuprates, n-Bu(FG-C6H4)CuZnI and iodozinc din-butylcuprate, n-Bu2CuZnI with benzoyl chloride in THF at 15-(-15)°C. Third order reaction was found which is first order in benzoyl chloride and second order in cuprate. We offered a reaction mechanism for the acylation of halozinc diorganocuprates depending on the kinetic data and activation parameters. Lower reaction rate of transferable group, n-Bu in mixed cuprate, n-Bu(PhCuZnI than that of homocuprate, n-Bu2CuZnI and Hammett correlation of the reaction rate of transferable group, n-Bu in n-Bu(FG-C6H4)CuZnI reagents with the substituent constants of residual group, FG-C6H4 with a positive reaction constant (relative reactivity of FG: 4-Br >3-MeO > H > 3-Me > 4-Me > 4-MeO) are in accordance with the proposed mechanism. These findings support our hypothesis that the reaction rate of transferable group, R T changes depending on the residual group, RR in mixed cuprates. RRRTCuM (M = Li, MgX, ZnX) and also provide a kinetic explanation for the commonly accepted hypothesis regarding the dependence of the RT group transfer ability on the strength of the R ReCu bond in mixed cuprates, RRRTCuLi. © 2013 Elsevier B.V. All rights reserved.