ic401744h_si_002.cif (174.92 kB)
Reaction of 13-Vertex Carborane μ‑1,2-(CH2)4‑1,2‑C2B11H11 with Nucleophiles: Linkage Effect on Product Formation
datasetposted on 2013-09-16, 00:00 authored by Jian Zhang, Zuowei Xie
The length of C,C′-linkage has a great influence on the reactivity of 13-vertex carboranes. Reaction of 1,2-(CH2)4-1,2-C2B11H11 (1a) with Et2NH gave a 1:1 adduct nido-7-NEt2H-μ-1,3-(CH2)4-1,3-C2B11H11 (2). Compound 1a reacted with Me2NLi or Et2NLi to afford nido-[9-Nu-μ-7,8,10-(CH2)4CCH-B11H10]− (Nu = NMe2, −; Nu = NEt2, −). Complex − was also obtained by deprotonation of 2. Treatment of 1a with MeOH/base generated nido-[3-OMe-μ-1,2-(CH2)4-1,2-C2B11H11]− (−) at room temperature, which was converted to nido-[μ-7,8-(CH2)4CHB(OMe)2-7-CB10H11]− (−) upon heating in the presence of Et3N. Complex − was oxidized by H2O2 to the corresponding alcohol [μ-7,8-(CH2)4CHOH-7-CB10H11]− (−) or hydrolyzed to the boronic acid [μ-7,8-(CH2)4CHB(OH)2-7-CB10H11]− (−). Reaction of 1a with (4-MeC6H4)SNa produced a CB11– anion closo-[μ-1,2-(CH2)4CHS(4-MeC6H4)-1-CB11H10]− (−). The above complexes were fully characterized by 1H, 13C, and 11B NMR spectroscopic data and elemental analyses. Molecular structures of 1–− and − were further confirmed by single-crystal X-ray analyses.