Reactions of closo-dodecaborate amines. Towards novel bis-(closo-dodecaborates) and closo-dodecaborate conjugates with lipids and non-natural nucleosides

Alkylation, acylation and arylation reactions of closo-dodecaborate based amines were studied. First, bis(closo-dodecaborate) species with terminal amino group tethered via linkers of different types were prepared by cleavage of cyclic oxonium adducts of closo-dodecaborate with closo-dodecaborate tertiary amines. Acylation of [B12H11OCH2CH2OCH2CH2N+H3](2-) with fatty acid acyl chlorides afforded new closo-dodecaborate lipid amides. Reaction of [B12H11OCH2CH2OCH2CH2N+H3](2-) with 4-chloro-1-(2-deoxy-3,5-di-O-(p-toluoyl)-beta-D-erythro-pentofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine followed by removal of protecting groups from the sugar residue resulted in the first conjugate of closo-dodecaborate with nonnatural 8-aza-7-deaza-2'-deoxyadenosine nucleoside analog. (C) 2016 Elsevier B.V. All rights reserved.