Synthesis of closo-1,2‑H2C2B8Me8 and 1,2‑H2C2B8Me7X (X = I and OTf) Dicarbaboranes and Their Rearrangement Reactions

• Published in: Inorganic chemistry Vol. 58; no. 4; pp. 2865 - 2871
• Main Authors: Bakardjiev, Mario, Růžička, Aleš, Růžičková, Zdeňka, Tok, Oleg L, Holub, Josef, Hnyk, Drahomír, Fanfrlík, Jindřich, Štíbr, Bohumil
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.02.2019
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.8b03550

Methyl-camouflaged dicarbaboranes closo-1,2- and 1,10-H2C2B8Me8 have been prepared in high yields either from nido-5,6-H2C2B8H10 or closo-1,2-H2C2B8H8 via electrophilic methylation reactions and cluster-rearrangement methods. Prepared were also monosubstituted derivatives of general formulation closo-H2C2B8Me7–X (X = I or OTf). The permethylated compounds exhibit extreme air stability in comparison to unprotected counterparts as a consequence of rigid, egg-shaped hydrocarbon structures incorporating inner C2B8 carborane scaffolding. The structures of all compounds isolated were confirmed unambiguously by multinuclear (11B, 1H, 13C, and 19F) NMR measurements, supported by X-ray diffraction analyses and geometry optimization methods on several compounds.