General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides

Bijay Shrestha, Surendra Thapa, Santosh K. Gurung, Ryan A.S. Pike, Ramesh Giri

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by β-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R2 = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.

Original languageEnglish (US)
Pages (from-to)787-802
Number of pages16
JournalJournal of Organic Chemistry
Volume81
Issue number3
DOIs
StatePublished - Feb 5 2016

All Science Journal Classification (ASJC) codes

  • Organic Chemistry

Fingerprint Dive into the research topics of 'General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides'. Together they form a unique fingerprint.

  • Cite this