Metathesis chemistry of inorganic cumulenes driven by B–O bond formation †

Journal article

The reaction chemistry of an unprecedented ‘inorganic cumulene’ – featuring a five-atom BNBNB chain – towards C 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 O (and related) multiple bonds is disclosed. In marked contrast to related all-carbon systems, the intrinsic polarity of the BNBNB chain (featuring electron-rich nitrogen and electron-deficient boron centres) enables metathesis chemistry with electrophilic heteroallenes such as CO2 and with organic carbonyl compounds. Transfer of the borylimide unit to [CO], [CS], [PP{(NDippCH2)2}] and [C(H)Ph] moieties generates (boryl)NCX systems (X = O, S, PP{(NDippCH2)2}, C(H)Ph), driven thermodynamically by B–O bond formation. Pairwise exchange of O and {(HCDippN)2}BN fragments occurs via consecutive [2+2] cyclo-addition/cyclo-reversion steps. An isolable complex of stoichiometry K[(boryl)NB(O)OC(H)Ph], formed via [2+2] cycloaddition to [(boryl)NBO]− can be shown to be an intermediate in the formation of (boryl)NC(H)Ph, and provides corroborating evidence for a DFT-calculated mechanism proceeding via a ‘bora-Wittig’ mechanism.

Authors: Tang, J; Hu, C; Crumpton, AE; Griffin, LP; Goicoechea, JM

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Chemical Science
• Publication date: 2024-12-18
• Acceptance date: 2024-12-16
• DOI: 10.1039/d4sc07487d
• EISSN: 2041-6539
• ISSN: 2041-6520
• Language: English