869118-25-2Relevant academic research and scientific papers
Synthesis of nickel-monocarbollide complexes by oxidative insertion
McGrath, Thomas D.,Franken, Andreas,Kautz, Jason A.,Stone, F. Gordon A.
, p. 8135 - 8144 (2005)
Treatment of the 11-vertex carborane anion [closo-2-CB10H 11]- with Ni(0) reagents in tetrahydrofuran (THF) affords - via oxidative insertion reactions - 12-vertex Ni(II) complexes, isolated as the salts [N(PPh3)2][2,2-L2-closo-2,1-NiCB 10H11] (L = CO (1a), CNBut (1b), and CNXyl (1c; Xyl = C6H3Me2-2,6); L2 = cod (1d; cod = 1,2:5,6-η-cyclo-octa-1,5-diene)). One CO ligand in 1a is readily replaced by donors L′ in the presence of Me3NO to give the species [N(PPh3)2][2-CO-2-L′-closo-2,1-NiCB 10H11] (L′ = PEt3 (1e), PPh3 (1f), CNBut (1g), and CNXyl (1h)). The anionic complexes themselves readily react with hydride abstracting reagents in the presence of donor ligands to yield zwitterionic complexes in which boron vertexes bear substituents that are bound through C, N, or O atoms. Thus, for example, 1c with H+ and CNXyl gives [2,2,7-(CNXyl)3-closo-2,1-NiCB10H 10] (2b), while 1f with Me+ in the presence of OEt 2 affords [2-CO-2,11-{μ-PPh2(C6H 4-o)}-7-OEt2-closo-2,1-NiCB10H9] (4), in which an additional cycloboronation of one phosphine phenyl ring has occurred. In contrast, 1f with Me+ in the presence of NCMe gives a mixture of the isomers [2-CO-2-PPh3-7-{(X)-N(Me)=C(H)Me}-closo-2,1- NiCB10H10] (X ≡ E (5c) and Z (5d)). X-ray diffraction analyses of compounds 1a, 2b, 4, and 5c confirmed their important structural features.
