American Chemical Society
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

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posted 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, [3]; Nu = NEt2, [4]). Complex [4] 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] ([5]) at room temperature, which was converted to nido-[μ-7,8-(CH2)4CHB­(OMe)2-7-CB10H11] ([6]) upon heating in the presence of Et3N. Complex [6] was oxidized by H2O2 to the corresponding alcohol [μ-7,8-(CH2)4CHOH-7-CB10H11] ([7]) or hydrolyzed to the boronic acid [μ-7,8-(CH2)4CHB­(OH)2-7-CB10H11] ([8]). Reaction of 1a with (4-MeC6H4)­SNa produced a CB11 anion closo-[μ-1,2-(CH2)4CHS­(4-MeC6H4)-1-CB11H10] ([9]). The above complexes were fully characterized by 1H, 13C, and 11B NMR spectroscopic data and elemental analyses. Molecular structures of 1–[7] and [9] were further confirmed by single-crystal X-ray analyses.