Selective sp3 C-H activation of ketones at the β position by Ir(I). Origin of regioselectivity and water effect

Moran Feller, Amir Karton, Gregory Leitus, Jan M L Martin, David Milstein

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

The reaction of the cationic (PNP)Ir(I)(cyclooctene) complex (1) (PNP = 2,6-bis-(di-tert-butylphosphinomethyl)pyridine) with 2-butanone or 3-pentanone results in the selective, quantitative activation of a β C-H bond, yielding O,C-chelated complexes. Calculations show that the selectivity is both kinetically (because of steric reasons in the rate determingin step (RDS)) and thermodynamically controlled, the latter as a result of carbonyl oxygen coordination in the product. The RDS is formation of the η2-C,H intermediates from the complexed ketone intermediates. Water has a strong influence on the regioselectivity, and in its presence, reaction of 1 with 2-butanone gives also the α terminal C-H activation product. Computational studies suggest that water can stabilize the terminal α C-H activation product by hydrogen bonding, forming a six-membered ring with the ketone, as experimentally observed in the X-ray structure of the acetonyl hydride aqua complex.

Original languageEnglish
Pages (from-to)12400-12401
Number of pages2
JournalJournal of the American Chemical Society
Volume128
Issue number38
DOIs
Publication statusPublished - Sep 27 2006

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Regioselectivity
Ketones
Pentanones
Chemical activation
Hydrogen
Water
Hydrogen Bonding
X-Rays
Oxygen
Hydrides
Pyridine
Hydrogen bonds
X rays
methylethyl ketone
pyridine

ASJC Scopus subject areas

  • Chemistry(all)

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Selective sp3 C-H activation of ketones at the β position by Ir(I). Origin of regioselectivity and water effect. / Feller, Moran; Karton, Amir; Leitus, Gregory; Martin, Jan M L; Milstein, David.

In: Journal of the American Chemical Society, Vol. 128, No. 38, 27.09.2006, p. 12400-12401.

Research output: Contribution to journalArticle

Feller, Moran ; Karton, Amir ; Leitus, Gregory ; Martin, Jan M L ; Milstein, David. / Selective sp3 C-H activation of ketones at the β position by Ir(I). Origin of regioselectivity and water effect. In: Journal of the American Chemical Society. 2006 ; Vol. 128, No. 38. pp. 12400-12401.
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