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Allylic C-H acetoxylation with a 4,5-diazafluorenone-ligated palladium catalyst: a ligand-based strategy to achieve aerobic catalytic turnover.

ABSTRACT: Pd-catalyzed C-H oxidation reactions often require the use of oxidants other than O(2). Here we demonstrate a ligand-based strategy to replace benzoquinone with O(2) as the stoichiometric oxidant in Pd-catalyzed allylic C-H acetoxylation. Use of 4,5-diazafluorenone (1) as an ancillary ligand for Pd(OAc)(2) enables terminal alkenes to be converted to linear allylic acetoxylation products in good yields and selectivity under 1 atm O(2). Mechanistic studies have revealed that 1 facilitates C-O reductive elimination from a ?-allyl-Pd(II) intermediate, thereby eliminating the requirement for benzoquinone in this key catalytic step.

SUBMITTER: Campbell AN

PROVIDER: S-EPMC2971663 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature

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Allylic C-H acetoxylation with a 4,5-diazafluorenone-ligated palladium catalyst: a ligand-based strategy to achieve aerobic catalytic turnover.

Campbell Alison N AN White Paul B PB Guzei Ilia A IA Stahl Shannon S SS

Journal of the American Chemical Society 20101101 43

Pd-catalyzed C-H oxidation reactions often require the use of oxidants other than O(2). Here we demonstrate a ligand-based strategy to replace benzoquinone with O(2) as the stoichiometric oxidant in Pd-catalyzed allylic C-H acetoxylation. Use of 4,5-diazafluorenone (1) as an ancillary ligand for Pd(OAc)(2) enables terminal alkenes to be converted to linear allylic acetoxylation products in good yields and selectivity under 1 atm O(2). Mechanistic studies have revealed that 1 facilitates C-O redu ...[more]

PMID: 20929224

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