The selective placement of substituents on the boron vertices of the three isomeric icosahedral C,B,,H,, carboranes remains as a major target of synthetic strategies."] At the same time, the attachment of functional groups to the carbon vertices and their subsequent conversion is relatively well developed[', since the C H vertices of the parent carboranes may be deprotonated with strong bases and the resulting carbanions employed as nucleophilic reagents. The principal mode of reaction of the BH vertices has been attack by electrophilic reagents leading to halogenation. metalation, or alkylation. ['. '] The nature of the products that result from these electrophilic substitution reactions are very dependent upon the identity of the carborane isomer employed as the substrate.The three isomeric icosahedral C,B,,H,, carboranes are frequently suggested as structural components for molecular scaffoldingL4] and supramolecular constructs.[51 These applications of carboranes might be better served if the BH and C H vertices were converted to their chemically stable and hydrophobically enhanced BCH, and CCH, counterparts. Completely sheathing an icosahedral carborane with methyl groups would provide a form of camouflage for the underlying polyhedral borane framework and produce a molecule whose exterior resembles a hydrocarbon, but whose superstructure is that of a polyhedral borane. Consequently, one might expect the external (CH,), sheath to reduce the reactivity characteristic of the carborane skeleton['* ' I while at the same time presenting opportunities for typical hydrocarbon reactions in an unusual environment. Such compounds would also be expected to exhibit the excellent thermal stability characteristic of carboranes and unsurpassed hydrophobicity. Until now, no successful syntheses have been reported leading to fully alkylated icosahedral carboranes, although a few low-yielding routes are known for the smaller carboranes.[61 and partial substitution of icosahedral carboranes leads to mixtures of isomers which can be difficult or impossible to separate. We here report high-yielding syntheses of 1 ,I 2-dicarba-closo-dodecaborane(I2) derivatives in which all boron vertices are methylated and one or both carbon vertices are either methylated or remain as CH vertices available for lithiation and further reactions.Permethylated 1,12-dicarba-closo-dodecaborane(l2) (1) was obtained in 91 YO isolated yield by reaction of 1,12-dimethyl-1,12-dicarba-closo-dodecaborane( 12)r7a1 with neat methyl trifluoromethanelsulfonate (methyl triflate) and small quantities of trifluoromethanesulfonic acid (triflic acid) acting as a catalyst at reflux for 20 h (Scheme 1). The identity of 1 was clearly indicated by the presence of a single signal in the I'B N M R spectrum with no coupling to hydrogen. The crude reaction products when subjected to GC/MS analysis revealed that the reaction had gone to completion; no species having less than twelve methyl groups was present. Similarly, reaction of 1,12-dicarba-closo-dodecaborane ( 12) BMe ...

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BackgroundTissue factor pathway inhibitor-2 (TFPI-2) is an extracellular matrix associated broad-spectrum Kunitz-type serine proteinase inhibitor. Recently, down regulation of TFPI-2 was suggested to be involved in tumor invasion and metastasis in some cancers.MethodsThis study involved 12 normal cervical squamous epithelia, 48 cervical intraepithelial neoplasia (CIN), and 68 cervical cancer. The expression of TFPI-2, Ki-67 and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining. The apoptolic index(AI) was determined with an in situ end-labeling assay(TUNEL). And the marker of CD34 staining was used as an indicator of microvessel density (MVD).ResultsTFPI-2 expression has a decreasing trend with the progression of cervical cancer and was significantly correlated with FIGO stage, lymph node metastasis and HPV infection. In addition, there were significant positive correlations between the grading of TFPI-2 expression and AI(P = 0.004). In contrast, the expression of TFPI-2 and VEGF or MVD was negatively correlated (both p < 0.001). However, we did not establish any significant correlation between Ki-67 and TFPI-2 expression in cervical cancer.ConclusionsThe results suggested that the expression of TFPI-2 had a decreasing trend with tumor progression of cervical cancer. There was a close association between the expression of TFPI-2 and tumor cell apoptosis and angiogenesis in patients with cervical cancer. TFPI-2 may play an inhibitive role during the development of cervical cancer.

Reaction of closo-1,12-C2B10H12 (para-carborane) with 2 molar equiv of IC1 in the presence of catalytic quantities of AICI3 affords closo-1,12-C2B;oH 10I2 as a mixture of isomers. The 2,9-(2), 2,3-(3), and 2,7-isomers (4) have been isolated and characterized. Reaction of closo-1,12-C2BioHh-2-I (1) with PhMgBr or 2 with RMgBr (R = Me, Ph) in the presence of PdCl2(PPh3)2 and Cul gives high yields of closo-1,12-C2B10H11 -2-Ph (6) and closo-1,12-C2BioHio-2,9-R2 (7, R = Me; 8, R = Ph), respectively. Reaction of 1 with HC=CPh in the presence of PdCl2(PPh3)2 and pyrrolidine yields closo-1,12-C2B1 oH 11 -2-C=CPh (9). Reaction of 1 or 2 with HC=CSiMe3 under the same conditions affords closo-1,12-C2B1 oH 11 -2-C=CSiMe3 (10) and c/050-1,12-C2B1 oH 11-2,9-(C=CSiMe3)2 ( 12) which react with fluoride ion to give closo-1,12-C2B10H11 -2-C=CH (11) and closo-1,12-C2B10H1 i-2,9-(C=CH)2 ( 13), respectively. The structures of 1, 3, 4, closo-LI2-C2H2B10I10 (5), and 8 have been determined by crystallographic studies. Crystallographic data are as follows: For 1, monoclinic, space group C2/c, a = 10.824(2) k,b = 9.439(1) A, c = 21.414(3) k,0= 102.