53257-04-8Relevant articles and documents
On the reactions of haloidmagnesiummethyl-m-carboranes with organoalkoxysilanes and chlorosilanes
Izmaylov, Boris A.,Vasnev, Valerii A.,Markova, Galy D.
, p. 475 - 480 (2017/12/07)
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.
11B NMR Probes of Copper(II): Finding and Implications of the Cu2+-Promoted Decomposition of ortho-Carborane Derivatives
Tanaka, Tomohiro,Nishiura, Yukiko,Araki, Rikita,Saido, Takaomi,Abe, Ryo,Aoki, Shin
, p. 1819 - 1834 (2016/05/02)
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+.
