Fluorination of deltahedral closo-borane and -carborane anions with N-fluoro reagents

Ivanov, S. V.; Lupinetti, Anthony J.; Солнцев, К. А.; Strauss, Steven H.

doi:10.1016/s0022-1139(98)00088-8

Cited by 46 publications

(12 citation statements)

References 24 publications

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“…Even closo -1,2-C 2 B 8 H 10 ( 1 ), a smaller analogue of the popular o -carborane, undergoes electrophilic halogenation at boron vertexes most remote from both carbon vertexes with a maximum number of two substituents under the relatively mild conditions employed. However, in comparison to the isoelectronic [1-CB 9 H 10 ] − , and 1-SB 9 H 9 compounds, carborane 1 seems to be less reactive, most likely due to the presence of two positively charged carbon vertexes . The B7 and B10 positions, being most removed from the carbon vertexes, are preferred for electrophilic attack, perhaps unlike the aforementioned monoheteroborane compounds, in which the lower-belt B6 position is typically activated in the first step of a similar substitution.…”

Section: Discussionmentioning

confidence: 96%

Electrophilic Halogenation of closo-1,2-C₂B₈H₁₀

et al. 2017

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Initial studies on electrophilic halogenation of the dicarbaborane closo-1,2-CBH (1) have been carried out to reveal that the substitution takes place at B7 and B10 vertexes, which are the most removed from the CH positions. The course of the halogenation is strongly dependent on the nature of the halogenation agent and reaction conditions. Individual reactions led to the isolation of the monosubstituted compounds 1,2-CBH-10-X (2) (where X = F, I) and 1,2-CBH-7-X (3) (where X = Cl, I). Disubstituted carboranes 1,2-CBH-7,10-X (4) (where X = Cl, Br, I) were obtained under more forcing conditions. Individual halo derivatives were characterized by mass spectrometry and high-field NMR (B, H,C) spectroscopy combined with two-dimensional [B-B]-COSY, H{B(selective)}, and [B-H]-correlation NMR techniques. All of the derivatives bearing a halogen substituent in the B10 position exhibit a remarkable antipodal C andH NMR shielding at the CH1 vertex, increasing in the order H < I < Br < Cl < F. The structures of 1,2-CBH-7,10-X derivatives (where X = Cl, I, 4b,d) were established by X-ray diffraction analyses.

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Section: Discussionmentioning

confidence: 96%

Electrophilic Halogenation of closo-1,2-C₂B₈H₁₀

et al. 2017

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“…A more detailed description of the isolated products is given in section 8.4.1, and a possible reaction mechanism is shown. 44 2, Br2, AcOH 174 16 1, NCS, DMF 199 44 2, DME, ICl 175 16 1, NBS, DMF 201 45 2, Cl2, AcOH 175 16 1, Br2, K2CO3 202 41 2, Br2, TfOH 176 21 1, I2, KOH, H2O c 203 41 2, ICl 176 13 1, I2, AcOH 207 13 3, ICl, DME 177 21 1, AcOH, Cl2 212 13 11, ICl, DME 178 21 1, AcOH, Br2 239 b, 53 1, F-TEDA 179 39 1, DME, ICl 247 b, 53 1, F-TEDA 180 40 1, F2/HF 248 16 1, NCS, DMF 182 41 1, Br2, TfOH 249 16 1, NBS, DMF 183 41 1, ICl 250 21 1, I2, AcOH 184 41 1, Br2, TfOH 250 16 224, I2 185 42 145, I2, AlCl3 53 1, F-TEDA 186 31 137, ICl, AcOH 255 21 1, AcOH, Cl2 187 43 142, ICl, TfOH 393 b,53 1, F-TEDA 188 43 142 …”

Section: Nucleophilicmentioning

confidence: 99%

“…Low-Symmetry CB11 Anions (cf. Figure 1) compound compound 228 51 2-Ph-CB11H11 -248 16 7,12-Cl2-CB11H10 -229 51 2-(p-MeC6H4)-CB11H11 -249 16 7,12-Br2-CB11H10 -230 51 2-Me3N-CB11H11 250 16 7,12-I2-CB11H10 -231 52 2-EtO-CB11H11 -251 42 1-Me3N-2-Ph-8-CH2dCHCH2-CB11H9 232 51 2-Cl(CH2)4O-CB11H11 -252 42 1-Me3N-2-Ph-8-Br-CB11H9 233 51 2-F-CB11H11 -253 42 1-Me2HN-2-Ph-8-I-CB11H9 234 52 2-Cl-CB11H11 -254 53 7,9,12-F3-CB11H9 -235 52 2-Br-CB11H11 -255 21 7,8,9,10,12-Cl5-CB11H7 -236 16 7-C6F5-CB11H11 -256 57 1-H-7,12-Cl2-CB11Me9 -237 32 7-H3N-CB11H11 257 50 1-H-CB11H9(HgOCOCF3)2 -238 32 7-Me3N-CB11H11 258 58 Rh(PPh3)2(7-Et-CB11H11) 239 53 7-F-CB11H11 -259 58 [Rh(PPh3)2(nbd)][7-Et-CB11H11] 240 54 1-Me2HN-2-iPr2NHCH2-CB11H10 260 58 Rh(PPh3)2(7-(CH2dCH)-CB11H11) 241 55 1-Me2N-2-HS-CB11H10 -261 58 [Rh(PPh3)2(nbd)][7-(CH2dCH)-CB11H11] 242 55 1-Me2N-2-Me2S-CB11H10 262 58 [Rh(PPh3)2(1-Me-Et3CB11H8] 243 56 1-Me2N-7-PhCH2-CB11H10 -263 58 [Rh(PPh3)2(NCMe)2,3][1-Me-Et3-CB11H8 ] 244 56 1-Me3N-7-PhCH2-CB11H10 264 58 [Rh(PPh3)2(NCMe)2,3][1-Me-Hex3-CB11H8] 245 55 1-Me2N-7-Et3N-CB11H10 265 58 Rh(PPh3)2-1-H-Et5-CB11H6 246 38 2,12-F2-CB11H10 -266 58 [Rh(PPh3)2(nbd)][1-H-Et5CB11H6] 247 53 7,12-F2-CB11H10 -syntheses have reasonable yields...…”

Section: Introductionmentioning

confidence: 99%

Chemistry of the Carba-closo-dodecaborate(−) Anion, CB₁₁H₁₂^-

2006

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“…This significant result suggests that fluorinated derivatives of CB 11 H 12 - might be even more weakly coordinating than the corresponding chlorinated, brominated, or iodinated derivatives, at least for some cations. For this reason, we have been developing synthetic strategies for the polyfluorination of CB 11 H 12 - and the related carborane ion CB 9 H 10 - has resulted in mixtures of ions of varying composition .…”

mentioning

confidence: 99%

“…For this reason, we have been developing synthetic strategies for the polyfluorination of CB 11 H 12 - and the related carborane ion CB 9 H 10 - has resulted in mixtures of ions of varying composition . For example, CB 11 H 12 - was converted to a mixture of CB 11 H 7 F 5 - (35%), CB 11 H 6 F 6 - (59%), and CB 11 H 5 F 7 - (6%) using anhydrous HF at 390 °C 9e.…”

mentioning

confidence: 99%