On the reactions of haloidmagnesiummethyl-m-carboranes with organoalkoxysilanes and chlorosilanes

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.