- Improved synthesis of MC4-PPEA and the biological evaluation of its hydroxymethyl derivative
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Nicotinamide phosphoribosyltransferase (Nampt) is an intriguing target for the treatment of many diseases, including cancer. Previously, our group demonstrated that carborane clusters may be used to increase the potency of small molecule inhibitors of Nam
- Sadrerafi, Keivan,Zargham, Emilia O.,Lee, Mark W.
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- On the reactions of haloidmagnesiummethyl-m-carboranes with organoalkoxysilanes and chlorosilanes
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For the first time an effective method for the preparation of 1-methoxy(dimethyl)silylmethyl-m-carborane and 1,7-bis[chloro(dimethyl)silylmethyl]-m-carborane using 1-haloidmagnesiummethyl-m-carborane and 1,7-bis[haloidmagnesiummethyl]-m-carborane was developed. It has been established that in the course of the reaction of 1-haloidmethyl-m-carboranes with magnesium both in ether and THF, simultaneously with the formation of 1-haloidmagnesiummethyl-m-carborane – the resulting Grignard reagent, proceeds the isomerization of carborane products and their remetallization with the obtained Grignard reagent. This leads to the formation of a complex mixture of products and the decrease in the yield of the resulting Grignard reagent to 43–67%. It has been shown that by using 1-haloidmethyl-m-carboranes substituted in the second carbon atom, for example, 1,7-bis[bromomethyl]-m-carborane, in the reactions for obtaining Grignard reagents, it is possible to eliminate the isomerization of carborane products and their remetallization with the target Grignard reagent 1,7-bis[bromomagnesiummethyl]-m-carborane in 90% yield.
- Izmaylov, Boris A.,Vasnev, Valerii A.,Markova, Galy D.
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- Preparation method of 1,7-m-carborane dihydroxyl substituted derivative
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The invention relates to a preparation method of a 1,7-m-carborane dihydroxyl substituted derivative, and belongs to the technical field of organic synthesis of carborane derivatives. The invention provides the preparation method of the 1,7-m-carborane dihydroxyl substituted derivative. The method comprises the following steps: (1) decaborane is reacted with a compound shown in a formula VI, and separation is performed to obtain a compound shown in a formula III; (2) in an inert environment, the compound shown in the formula III is subjected to a rearrangement reaction at 200 to 400 DEG C, and separation is performed to obtain a compound shown in a formula II; (3) the compound shown in the formula II is subjected to an ester hydrolysis reaction, and separation is performed to obtain the 1,7-m-carborane dihydroxyl substituted derivative shown in a formula I. The method utilizes cheap and easily-available raw materials to prepare the 1,7-m-carborane dihydroxyl substituted derivative; the production cost of the 1,7-m-carborane dihydroxyl substituted derivative can be significantly reduced; the reaction process is gentle and easy to control; the product yield is high; a relatively good industrial application value is realized.
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Paragraph 0032-0033; 0042-0046; 0055-0058; 0063-0064
(2019/10/10)
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- 11B NMR Probes of Copper(II): Finding and Implications of the Cu2+-Promoted Decomposition of ortho-Carborane Derivatives
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The development of noninvasive methodologies for the detection of d-block metal ions such as copper (Cu2+), zinc (Zn2+), and manganese (Mn2+) is important for understanding their biological roles and relationship with diseases. We have been interested in the use of 11B NMR probes for the detection of d-block metal ions, because 11B is an ultratrace element in living systems. o-Carboranes, which consist of ten boron and two carbon atoms, have been applied to numerous drugs and biological active agents. In this work, we found that the o-carborane-pendant cyclens (L3-L5) (cyclen = 1,4,7,10-tetraazacyclododecane) are decomposed in the presence of Mn2+ or Cu2+ in aqueous solution at neutral pH, accompanied by the release of 4-9 equiv. of B(OH)3. Furthermore, it was found that o-carborane derivatives that contain hydroxyl groups instead of a cyclen unit also undergo decomposition in the presence of Cu2+ and the corresponding complexes such as Cu(bpy) to afford 10 equiv. of B(OH)3, as confirmed by 11B NMR spectroscopic analysis and an azomethine-H assay. These reactions are applied to 11B MRI (magnetic resonance imaging) probes for Cu2+.
- Tanaka, Tomohiro,Nishiura, Yukiko,Araki, Rikita,Saido, Takaomi,Abe, Ryo,Aoki, Shin
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p. 1819 - 1834
(2016/05/02)
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- Greatly enhanced thermo-oxidative stability of polybenzoxazine thermoset by incorporation of m-carborane
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Novel polybenzoxazine precursor containing m-carborane unit in the main-chain has been firstly synthesized through click reaction of diazidomethyl m-carborane (DAMC) and diacetylene bisbenzoxazine (DABB). Meanwhlie, the traditional polybenzoxazine precursor was also prepared through click reaction of diazidomethyl p-benzene (DAPB) and DABB as a control. 1H NMR was used to confirm the structures of the monomers and the resulting polymers. FT-IR and differential scanning calorimetry (DSC) were used to study the curing behavior of carborane-containing benzoxazine polymer (CCBP). Dynamic mechanical analysis (DMA) study demonstrated that the cured CCBP had high storage moduli and high Tg. Thermogravimetric analysis (TGA) and ablation test showed that the cured CCBP had outstanding thermo-oxidative stability. During thermal ablation of cured CCBP, organic material was degraded, and a passivation layer with oxidized m-carboranes was formed, which prevented the underlying polymer from further degradation.
- Huang, Xin,Zhang, Qiuhong,Meng, Zheng,Gu, Jiangjiang,Jia, Xudong,Xi, Kai
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p. 973 - 980
(2015/03/18)
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- Carborane-based pincers: Synthesis and structure of SeBSe and SBS Pd(II) complexes
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(Figure Presented) We report the synthesis of several unique, boron-rich pincer complexes derived from mcarborane. The SeBSe and SBS pincer ligands can be synthesized via two independent synthetic routes and are metalated with Pd(II). These structures rep
- Spokoyny, Alexander M.,Reuter, Matthew G.,Stern, Charlotte L.,Ratner, Mark A.,Seideman, Tamar,Mirkin, Chad A.
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p. 9482 - 9483
(2009/12/06)
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- Neocarboranes, a new family of stable organoboranes isomeric with the carboranes
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Heating of the recently described compound2 carborane, C2B10H12, at 465-500° for 24 hr. produced the first member of a new family of organoboranes. The name neocarborane has been assigned to this product, which is isomeric with the original carborane. The chemistry ot neocarborane has been explored and is compared to that of carborane. In general, neocarborane derivatives are less polar and more stable than their carborane isomers. As in thecarboranes, the C2B10H10 unit is unusually inert and many standard organic processes can be effected on organofunctional substituents attached to the neocarborane carbon atoms. Carborane is assigned the distorted icosahedral structure, A, with the two carbon atoms sharing a short, depressed edge of an otherwise regular icosahedron. A regular icosahedral structure, C or D, is suggested for neocarborane. Electronic structures and possible reaction paths are indicated.
- Grafstein, Daniel,Dvorak, Joseph
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p. 1128 - 1133
(2008/10/08)
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