title: New strategy for synthesis of mercaptoundecahydrododecaborate derivatives via click chemistry: possible boron carriers and visualization in cells for neutron capture therapy.
abstract: A new method that utilizes the click cycloaddition reaction to functionalize B(12)H(11)SH(2-) (BSH) with organic molecules was investigated. S,S-Dipropargyl-SB(12)H(11)(-) (1) and S-propargyl-SB(12)H(11)(2-) (4) were prepared from [(CH(3))(4)N](2)B(12)H(11)SH and [(CH(3))(4)N](2)B(12)H(11)S(CH(2))(2)CN (2) with propargyl bromide, respectively. Compound 1 or 4 reacted with various azides with mediation by Cu(II) ascorbate to give the corresponding bis-triazolo BSH derivatives (1-) or monotriazole BSH derivatives (2-), respectively, in excellent yields. The click cycloaddition reaction is very useful not only for the synthesis of various BSH-containing organic compounds for boron neutron capture therapy (BNCT) but also for the visualization of boron clusters in cells. We succeeded in the click cycloaddition reaction of compound 1 with Alexa Fluor 488 azide dye and found that 1 accumulated not in the cytoplasm but in the nuclei of HeLa cells.
authors.affiliation: Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: El-Zaria
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D001894:Borohydrides / Q000138:chemical synthesis* / Q000737:chemistry; D001895:Boron / Q000737:chemistry*; D002467:Cell Nucleus / Q000737:chemistry* / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D015394:Molecular Structure; D017247:Neutron Capture Therapy; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D001894:Borohydrides; D013438:Sulfhydryl Compounds; C014651:mercaptoundecahydrododecaborate; D003300:Copper; D001895:Boron; D001205:Ascorbic Acid