Regioselective synthesis of [1-B10H9(SH)]2– and [2-B10H9(SH)]2–: potential agents for boron–Neutron capture therapy of brain tumours

Abstract

The substitution reaction of [1-B₁₀H₉(N₂)]^– with N,N-dimethylthioformamide and the acid-catalyzed nucleophilic substitution of [B₁₀H₁₀]^2– with tetramethylthiourea gave [1-B₁₀H₉(SCHNMe₂)]^– and [2-B₁₀H₉{SC(NMe₂)₂}]^– respectively. The basic hydrolysis of these thioamide complexes yielded the 1- and 2-isomers of [B₁₀H₉(SH)]^2– respectively. Their stereochemistry was determined by ¹H n.m.r. spectroscopy from the S–Me chemical shift values of their S-methyl derivatives.