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Revisiting the Synthesis and Nucleophilic Reactivity of an Anionic Copper Superoxide Complex.

ABSTRACT: The addition of 1 equiv of KO2 and Kryptofix222 (Krypt) in CH3CN to a solution of LCu(CH3CN) [L = N, N'-bis(2,6-diisopropylphenyl)-2,6-pyridinecarboxamide] in tetrahydrofuran at -80 °C yielded [K(Krypt)][LCuO2], the enhanced stability of which enabled reexamination of its reactivity with 2-phenylpropionaldehyde (2-PPA). Mechanistic and product analysis studies revealed that [K(Krypt)][LCuO2] reacts with wet 2-PPA to form [LCuOH]-, which then deprotonates 2-PPA to yield the copper(II) enolate complex [LCu(OC?C(Me)Ph)]-. Acetophenone was observed upon workup of this complex or mixtures of KO2 and 2-PPA alone, in support of an alternative mechanism(s) to the one proposed previously involving an initial nucleophilic attack at the carbonyl group of 2-PPA.

SUBMITTER: Bailey WD

PROVIDER: S-EPMC6548509 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Revisiting the Synthesis and Nucleophilic Reactivity of an Anionic Copper Superoxide Complex.

Bailey Wilson D WD Gagnon Nicole L NL Elwell Courtney E CE Cramblitt Anna C AC Bouchey Caitlin J CJ Tolman William B WB

Inorganic chemistry 20190322 8

The addition of 1 equiv of KO2 and Kryptofix222 (Krypt) in CH3CN to a solution of LCu(CH3CN) [L = N, N'-bis(2,6-diisopropylphenyl)-2,6-pyridinecarboxamide] in tetrahydrofuran at -80 °C yielded [K(Krypt)][LCuO2], the enhanced stability of which enabled reexamination of its reactivity with 2-phenylpropionaldehyde (2-PPA). Mechanistic and product analysis studies revealed that [K(Krypt)][LCuO2] reacts with wet 2-PPA to form [LCuOH]-, ...[more]

PMID: 30901201

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