Synthesis of 3-Aryl-ortho-carboranes with Sensitive Functional Groups

Abstract

A simple and efficient method was developed for the one-pot synthesis of 3-aryl derivatives of ortho-carborane with sensitive functional groups using 3-iodo-ortho-carborane and aryl zinc bromides that were generated in situ. A series of 3-aryl-ortho-carboranes, including those containing nitrile and ester groups, 3-RC6H4-1,2-C2B10H11 (R = p-Me, p-NMe2, p-OCH2OMe, p-OMe, o-CN, p-CN, o-COOEt, m-COOEt, p-COOEt) was synthesized using this approach. The solid-state structures of 3-RC6H4-1,2-C2B10H11 (R = p-OMe, o-CN, and p-CN) were determined by single crystal X-ray diffraction. The intramolecular hydrogen bonding involving the ortho-substituents of the aryl ring and the CH and BH groups of carborane was discussed.

Synthesis and Crystal Structure of 9,12-Dibromo-ortho-Carborane

“…It should be noted that to date, a large number of various iodo derivatives of carboranes have been synthesized, differing in the position of the substituents and their number [20][21][22][23][24][25][26][27][28][29][30]. The increased interest in iodine derivatives of carborane is mainly caused by their use in various cross-coupling reactions [21][22][23][31][32][33][34][35][36][37][38][39][40], as well as in study of intermolecular hydrogen and halogen bonding [41,42] and medicinal chemistry [43]. Despite the fact that the bromination of carboranes was first described as early as the mid-1960s [44], the chemistry of bromo derivatives of carboranes has been studied to a much lesser extent compared to the iodo derivatives.…”