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Copper(ii) ketimides in sp³ C-H amination.

ABSTRACT: Commercially available benzophenone imine (HN[double bond, length as m-dash]CPh₂) reacts with β-diketiminato copper(ii) tert-butoxide complexes [Cu^II]-O ^t Bu to form isolable copper(ii) ketimides [Cu^II]-N[double bond, length as m-dash]CPh₂. Structural characterization of the three coordinate copper(ii) ketimide [Me₃NN]Cu-N[double bond, length as m-dash]CPh₂ reveals a short Cu-N_ketimide distance (1.700(2) Å) with a nearly linear Cu-N-C linkage (178.9(2)°). Copper(ii) ketimides [Cu^II]-N[double bond, length as m-dash]CPh₂ readily capture alkyl radicals R˙ (PhCH(˙)Me and Cy˙) to form the corresponding R-N[double bond, length as m-dash]CPh₂ products in a process that competes with N-N coupling of copper(ii) ketimides [Cu^II]-N[double bond, length as m-dash]CPh₂ to form the azine Ph₂C[double bond, length as m-dash]N-N[double bond, length as m-dash]CPh₂. Copper(ii) ketimides [Cu^II]-N[double bond, length as m-dash]CAr₂ serve as intermediates in catalytic sp³ C-H amination of substrates R-H with ketimines HN[double bond, length as m-dash]CAr₂ and ^t BuOO ^t Bu as oxidant to form N-alkyl ketimines R-N[double bond, length as m-dash]CAr₂. This protocol enables the use of unactivated sp³ C-H bonds to give R-N[double bond, length as m-dash]CAr₂ products easily converted to primary amines R-NH₂ via simple acidic deprotection.

SUBMITTER: Jayasooriya IU

PROVIDER: S-EPMC8654034 | biostudies-literature |

REPOSITORIES: biostudies-literature

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