FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W3034289989> ?p ?o ?g. }

• W3034289989 endingPage "7463" @default.
• W3034289989 startingPage "7449" @default.
• W3034289989 abstract "The oxidation state of the redox noninnocent tetra-amido macrocyclic ligand (TAML) scaffold was recently shown to affect the formation of nitrene radical species on cobalt(III) upon reaction with PhI═NNs [van Leest, N. P.; J. Am. Chem. Soc. 2020, 142, 552−563]. For the neutral [CoIII(TAMLsq)] complex, this leads to the doublet (S = 1/2) mono-nitrene radical species [CoIII(TAMLq)(N•Ns)(Y)] (bearing an unidentified sixth ligand Y in at least the frozen state), while a triplet (S = 1) bis-nitrene radical species [CoIII(TAMLq)(N•Ns)2]– is generated from the anionic [CoIII(TAMLred)]– complex. The one-electron-reduced Fischer-type nitrene radicals (N•Ns–) are formed through single (mono-nitrene) or double (bis-nitrene) ligand-to-substrate single-electron transfer (SET). In this work, we describe the reactivity and mechanisms of these nitrene radical complexes in catalytic aziridination. We report that [CoIII(TAMLsq)] and [CoIII(TAMLred)]– are both effective catalysts for chemoselective (C═C versus C–H bonds) and diastereoselective aziridination of styrene derivatives, cyclohexane, and 1-hexene under mild and even aerobic (for [CoIII(TAMLred)]–) conditions. Experimental (Hammett plots; [CoIII(TAML)]-nitrene radical formation and quantification under catalytic conditions; single-turnover experiments; and tests regarding catalyst decomposition, radical inhibition, and radical trapping) in combination with computational (density functional theory (DFT), N-electron valence state perturbation theory corrected complete active space self-consistent field (NEVPT2-CASSCF)) studies reveal that [CoIII(TAMLq)(N•Ns)(Y)], [CoIII(TAMLq)(N•Ns)2]–, and [CoIII(TAMLsq)(N•Ns)]– are key electrophilic intermediates in aziridination reactions. Surprisingly, the electrophilic one-electron-reduced Fischer-type nitrene radicals do not react as would be expected for nitrene radicals (i.e., via radical addition and radical rebound). Instead, nitrene transfer proceeds through unusual electronically asynchronous transition states, in which the (partial) styrene substrate to TAML ligand (single-) electron transfer precedes C–N coupling. The actual C–N bond formation processes are best described as involving a nucleophilic attack of the nitrene (radical) lone pair at the thus (partially) formed styrene radical cation. These processes are coupled to TAML-to-cobalt and cobalt-to-nitrene single-electron transfer, effectively leading to the formation of an amido-γ-benzyl radical (NsN––CH2–•CH–Ph) bound to an intermediate spin (S = 1) cobalt(III) center. Hence, the TAML moiety can be regarded to act as a transient electron acceptor, the cobalt center behaves as a spin shuttle, and the nitrene radical acts as a nucleophile. Such a mechanism was hitherto unknown for cobalt-catalyzed hypovalent group transfer and the more general transition-metal-catalyzed nitrene transfer to alkenes but is now shown to complement the known concerted and stepwise mechanisms for N-group transfer." @default.
• W3034289989 created "2020-06-19" @default.
• W3034289989 creator A5015653296 @default.
• W3034289989 creator A5029252935 @default.
• W3034289989 creator A5053264440 @default.
• W3034289989 creator A5064830068 @default.
• W3034289989 creator A5067204900 @default.
• W3034289989 creator A5071943748 @default.
• W3034289989 creator A5072907893 @default.
• W3034289989 date "2020-06-12" @default.
• W3034289989 modified "2023-10-01" @default.
• W3034289989 title "Electronically Asynchronous Transition States for C–N Bond Formation by Electrophilic <b>[Co^III(TAML)]</b>-Nitrene Radical Complexes Involving Substrate-to-Ligand Single-Electron Transfer and a Cobalt-Centered Spin Shuttle" @default.
• W3034289989 cites W1899165060 @default.
• W3034289989 cites W1969250743 @default.
• W3034289989 cites W1979149292 @default.
• W3034289989 cites W1985392598 @default.
• W3034289989 cites W1993198318 @default.
• W3034289989 cites W2028010226 @default.
• W3034289989 cites W2039501060 @default.
• W3034289989 cites W2064259630 @default.
• W3034289989 cites W2081070271 @default.
• W3034289989 cites W2082363306 @default.
• W3034289989 cites W2094376662 @default.
• W3034289989 cites W2097614647 @default.
• W3034289989 cites W2111918052 @default.
• W3034289989 cites W2127706988 @default.
• W3034289989 cites W2127716830 @default.
• W3034289989 cites W2131634514 @default.
• W3034289989 cites W2135733238 @default.
• W3034289989 cites W2154210943 @default.
• W3034289989 cites W2156001447 @default.
• W3034289989 cites W2165553732 @default.
• W3034289989 cites W2282184765 @default.
• W3034289989 cites W2287981370 @default.
• W3034289989 cites W2321378408 @default.
• W3034289989 cites W2325293649 @default.
• W3034289989 cites W2511904551 @default.
• W3034289989 cites W2569012662 @default.
• W3034289989 cites W2602973535 @default.
• W3034289989 cites W2605772266 @default.
• W3034289989 cites W2612152535 @default.
• W3034289989 cites W2722617707 @default.
• W3034289989 cites W2726731743 @default.
• W3034289989 cites W2758106511 @default.
• W3034289989 cites W2780590919 @default.
• W3034289989 cites W2792698118 @default.
• W3034289989 cites W2803459153 @default.
• W3034289989 cites W2887340290 @default.
• W3034289989 cites W2888012360 @default.
• W3034289989 cites W2890432142 @default.
• W3034289989 cites W2908521413 @default.
• W3034289989 cites W2917226464 @default.
• W3034289989 cites W2949921933 @default.
• W3034289989 cites W2950891723 @default.
• W3034289989 cites W2952728631 @default.
• W3034289989 cites W2952996055 @default.
• W3034289989 cites W2963450291 @default.
• W3034289989 cites W2969393238 @default.
• W3034289989 cites W2995293418 @default.
• W3034289989 cites W3005296830 @default.
• W3034289989 doi "https://doi.org/10.1021/acscatal.0c01343" @default.
• W3034289989 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/35912398" @default.
• W3034289989 hasPublicationYear "2020" @default.
• W3034289989 type Work @default.
• W3034289989 sameAs 3034289989 @default.
• W3034289989 citedByCount "24" @default.
• W3034289989 countsByYear W30342899892020 @default.
• W3034289989 countsByYear W30342899892021 @default.
• W3034289989 countsByYear W30342899892022 @default.
• W3034289989 countsByYear W30342899892023 @default.
• W3034289989 crossrefType "journal-article" @default.
• W3034289989 hasAuthorship W3034289989A5015653296 @default.
• W3034289989 hasAuthorship W3034289989A5029252935 @default.
• W3034289989 hasAuthorship W3034289989A5053264440 @default.
• W3034289989 hasAuthorship W3034289989A5064830068 @default.
• W3034289989 hasAuthorship W3034289989A5067204900 @default.
• W3034289989 hasAuthorship W3034289989A5071943748 @default.
• W3034289989 hasAuthorship W3034289989A5072907893 @default.
• W3034289989 hasBestOaLocation W30342899892 @default.
• W3034289989 hasConcept C116569031 @default.
• W3034289989 hasConcept C123669783 @default.
• W3034289989 hasConcept C139066938 @default.
• W3034289989 hasConcept C145148216 @default.
• W3034289989 hasConcept C155647269 @default.
• W3034289989 hasConcept C161790260 @default.
• W3034289989 hasConcept C170493617 @default.
• W3034289989 hasConcept C178790620 @default.
• W3034289989 hasConcept C185592680 @default.
• W3034289989 hasConcept C38489247 @default.
• W3034289989 hasConcept C50027330 @default.
• W3034289989 hasConcept C55493867 @default.
• W3034289989 hasConcept C71240020 @default.
• W3034289989 hasConcept C75473681 @default.
• W3034289989 hasConcept C96444392 @default.
• W3034289989 hasConceptScore W3034289989C116569031 @default.
• W3034289989 hasConceptScore W3034289989C123669783 @default.
• W3034289989 hasConceptScore W3034289989C139066938 @default.
• W3034289989 hasConceptScore W3034289989C145148216 @default.

• next