A simple route to essential tricarbollides. A high-yield synthesis of 7-amine-nido-7,8,9-tricarbaundecaboranes(10), 7-L-nido-7,8,9-C3B8H10 (where L =H3N, Me2NH, Me3N, and (BuH2N)-H-t)

Reported is an improved synthesis of essential starting compounds for the d evelopment of tricarbollide and metallatricarbollide chemistry. Evaporation of a solution of Na+[5,6-C2B8H11](-) (1(-)) in neat (BuNC)-N-t, followed b y acidification, led to the isolation of 7-((BuH2N)-H-t)-nido-7,8,9-C3B8H10 (2a) in a 90% yield. This was converted into the 7-(H3N)-nido-7,8,9-C3B8H1 0 (2b) derivative via reaction with AlCl3 in refluxing benzene (yield 77%), Methylation of 2b with Me2SO4 in an alkaline solution gave the 7-(Me3N)-ni do-7,8,9-C3B8H10 (2c) derivative in essentially quantitative yield. The rea ction of 2c with sodium in liquid ammonia resulted in the formation of high ly pure compounds 7-(Me2HN)-nido-7,8,9-C3B8H10 (2d) (yield 71%) and nido-7, 8,9-C3B8H12 (3) (yield 19%). (C) 1999 Elsevier Science S.A. All rights rese rved.