Some Recent Advances in the Chemistry of Dicarba-clos O-dodeca- Boranes(12), B1 0h1 0c 2rr'

Experimental data on the mutual rearrangements of isomeric dicarba-closododecaboranes(12) and their B-halogen derivatives are reviewed. Reactions involving electron transfer to dicarba-closo-dodecaboranes(12), and the properties of the resulting dodecahydrodicarba-nido-dodecaborates(2 —) as intermediates of the rearrangements of 1.7and 1,12-dicarba-closo-dodecaboranes(12) are discussed. Attention is also paid to the introduction of an NH2 group into 1,2-dicarba-closo-dodecaborane(12) via the formation of dodecahydro-1,2-dicarba-nido-dodecaborate(2 —) and to the reactions of 3-amino1,2-dicarba-closo-dodecaborane( 12). INTRODUCTION in 1963 Russian and American chemists were the first to report on dicarbacloso-dodecaboranes(12) and to stimulate interest in carborane chemistry which was generally directed towards the following: (a) Investigation of the properties of dicarba-closo-dodecaboranes(12); (b) Synthesis and study of novel dicarba-closo-boranes and heterocarboranes; (c) Preparation and study of metalcarboranes—cyclopentadienyl analogues of transition metal derivatives, This paper is concerned with experimental work on the mutual rearrangements of dicarba-closo-dodecaboranes and also with the related topic of the properties of dodecahydrodicarba-nido-dodecaborates(2 —) and 3amino-i ,2-dicarba-closo-dodecaboranes. Part of this work has been carried out at the Institute of Organo-Element Compounds in Moscow. MUTUAL REARRANGEMENTS OF ISOMERIC DICARBA-CLOSO-DODECABORANES(12yr Thermal rearrangements of isomeric carboranes One of the specific features of isomeric carboranes is their ability to undergo mutual rearrangements. In 1963 on the basis of theoretical calculations For convenience the following nomenc1atur is used in this paper: carborane = dicarbacloso-dodecaborane(l 2); o-carborane, m-carborane and p-carborane = 1,2-, 1,7and 1 12dicarba-closo-dodecaboranes (12), respectively.