Single Electron Transfer to Diazomethane–Borane Adducts Prompts C−H Bond Activations

• Published in: Angewandte Chemie International Edition Vol. 58; no. 51; pp. 18487 - 18491
• Main Authors: Cao, Levy L., Zhou, Jiliang, Qu, Zheng‐Wang, Stephan, Douglas W.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 16.12.2019; Wiley Subscription Services, Inc; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Adducts; Anions; borane; Chemistry; Chemistry, Multidisciplinary; Communication; Communications; DFT; Diazomethane; Electron transfer; Electrons; Hydrogen bonds; one-electron reduction; Physical Sciences; radical anions; Science & Technology; Single electrons; AUXILIARY BASIS-SETS; diazomethane; CATALYTIC-REDUCTION; AMMONIA; radical anions; DINITROGEN FIXATION; MOLYBDENUM; FRUSTRATED LEWIS PAIRS; ZETA-VALENCE QUALITY; NITROUS-OXIDE; DFT; CHEMISTRY; BINDING; one-electron reduction; borane
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201912338

While (Ph2CN2)B(C6F5)3 is unstable, single electron transfer from Cp*2Co affords the isolation of stable products [Cp*2Co][Ph2CNNHB(C6F5)3] 1 and [Cp*Co(C5Me4CH2B(C6F5)3)] 2. The analogous combination of Ph2CN2 and BPh3 showed no evidence of adduct formation and yet single electron transfer from Cp*2Cr affords the species [Cp*2Cr][PhC(C6H4)NNBPh3] 3 and [Cp*2Cr][Ph2CNNHBPh3] 4. Computations showed both reactions proceed via transient radical anions of the diphenyldiazomethane–borane adducts to effect C−H bond activations. Single electron transfer to diphenyldiazomethane–borane adducts generates transient radical anions that effect C−H bond activations. Such reductions provide a strategy to stabilize weak and even undetectable donor–acceptor adducts.