Synthesis and Structure of <i>Nido</i>-Carboranyl Azide and Its “Click” Reactions

oleh: Anna A. Druzina, Olga B. Zhidkova, Nadezhda V. Dudarova, Irina D. Kosenko, Ivan V. Ananyev, Sergey V. Timofeev, Vladimir I. Bregadze

Format: Article
Diterbitkan: MDPI AG 2021-01-01

Deskripsi

Novel zwitter-ionic <i>nido</i>-carboranyl azide 9-N<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>Me<sub>2</sub>N-<i>nido</i>-7,8-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub> was prepared by the reaction of 9-Cl(CH<sub>2</sub>)<sub>3</sub>Me<sub>2</sub>N-<i>nido</i>-7,8-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub> with NaN<sub>3</sub>. The solid-state molecular structure of <i>nido</i>-carboranyl azide was determined by single-crystal X-ray diffraction. 9-N<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>Me<sub>2</sub>N-<i>nido</i>-7,8-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub> was used for the copper(I)-catalyzed azide-alkyne cycloaddition with phenylacetylene, alkynyl-3β-cholesterol and cobalt/iron bis(dicarbollide) terminal alkynes to form the target 1,2,3-triazoles. The <i>nido</i>-carborane-cholesterol conjugate 9-3β-Chol-O(CH<sub>2</sub>)C-CH-N<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>Me<sub>2</sub>N-<i>nido</i>-7,8-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub> with charge-compensated group in a linker can be used as a precursor for preparation of liposomes for Boron Neutron Capture Therapy (BNCT). A series of novel zwitter-ionic boron-enriched cluster compounds bearing a 1,2,3-triazol-metallacarborane-carborane conjugated system was synthesized. Prepared conjugates contain a large amount of boron atom in the biomolecule and potentially can be used for BNCT.