Electrophilic substitution of the nido-dicarbaborate anion 7,8-nido-C2B9H12− with sulfenyl chlorides

Abstract

Sulfenyl chlorides RSCl (R = p-C₆H₄OMe, Ph, p-C₆H₄NO₂, CN or 2-C₅H₄N) react with 7,8-nido-C₂B₉H₁₂⁻ with asymmetric substitution on the pentagonal C₂B₃ face to give 9-RS-7,8-nido-C₂B₉H₁₁⁻ (R = p-C₆H₄OMe (3), Ph (4), p-C₆H₄NO₂ (5), CN (6)) and the zwitterion 9-(S-2-C₅H₄NH)-7,8-nido-C₂B₉H₁₁ (7), respectively, in high yield, while tBuSCl did not react and S₂Cl₂ led to decomposition. Further reaction of 5–7 with iodine gave the corresponding iodo derivatives NMe₄ [9-I-11-RS-7,8-nido-C₂B₉H₁₀] (R = p-C₆H₄NO₂ (8), CN (9)) and the zwitterion 9-I-11-(S-2-C₅H₄NH)-7,8-nido-C₂B₉H₁₁ (10), respectively. Compounds 3–10 were fully characterised by ¹H, ¹¹B, ¹¹B{¹H}, ¹³C{¹H} spectroscopy, IR spectroscopy, mass spectrometry and elemental analysis, 3–7 also by ¹¹B-¹¹B{¹H} COSY NMR spectroscopy and 8–10 by X-ray structure determination.