“Click” Chemistry-Mediated Phenylene-Cored Carborane Dendrimers

Abstract

Phenylene-cored small dendrimers containing three to nine peripheral o-carborane clusters were synthesized via Cu(I)-catalyzed Huisgen-type azide alkyne cycloaddition reactions. The resulting dendrimers have been characterized by IR and NMR spectroscopy and MALDI-TOF mass spectral analysis. The biological evaluation of branched dendrimer 16 containing nine carborane cages has been carried out using human liver cancer cells (SK-Hep1). Dendrimer 16 was accumulated in the SK-Hep1 cancer cells in a concentrationdependent manner. The highest boron accumulation up to 2540 ng of boron/5 × 10 5 cells was observed at a 50 μM concentration of 16 over a period of 20 h. The high accumulation of 16 into the tumor cell lines indicates that such dendritic boron drug delivery platforms could be possible for application in boron neutron capture therapy in cancer treatment.

Carboranes in the chemist's toolbox

“…12. 72 An example is a class of photoluminescent star-shaped dendrimers such as 1,3,5-[RCB 10 H 10 C-(CH 2 ) 3 OC 6 H 4 ] 3 C 6 H 3 (R = Me, Ph); removal of one boron from each carborane cage (deboronation) affords negatively charged water soluble nido-C 2 B 9 -based dendrimers.…”

Asymmetric AB3 Miktoarm Star Polymers: Synthesis, Self‐Assembly, and Study of Micelle Stability Using AF4 for Efficient Drug Delivery

“…It was initiated from a commercially available inexpensive compound, methyl‐3,4,5‐trihydroxybenzoate ( 1 ) which contains three –OH groups and a methyl ester. Propargylation of –OH groups of ( 1 ) was carried out using previously published procedure to give the desired tripropargylated derivative ( 2 ) . The methyl ester in ( 2 ) was then reduced to the corresponding alcohol using lithium aluminum hydride to give compound ( 3 ) .…”

“…Propargylation of –OH groups of ( 1 ) was carried out using previously published procedure to give the desired tripropargylated derivative ( 2 ) . The methyl ester in ( 2 ) was then reduced to the corresponding alcohol using lithium aluminum hydride to give compound ( 3 ) . The propargylated derivatives were subsequently used in three consecutive CuAAC click reactions to attach PEG chains, prepared from commercially available PEG 750 to yield polymer ( 4 ).…”

“…ϵ‐Caprolactone (99%), tin(II) 2‐ethylhexanoate (95%), copper(II) sulfate pentahydrate (CuSO 4 · 5H 2 O) (>98.0%), sodium ascorbate (NaAsc, crystalline, 98%), potassium carbonate (K 2 CO 3 ; anhydrous), lithium aluminum hydride (LiAlH 4 ; 95%), sodium azide (NaN 3 ; >99.5%), propargyl bromide solution (80 wt% in toluene), polyethylene glycol mono methyl ether, curcumin, phosphate‐buffered saline (PBS), 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT), propidium iodide (PI), and trypsin/EDTA (0.25%) were purchased from Sigma–Aldrich (St. Louis, MO, USA) and used as received. methyl‐3,4,5‐trihydroxybenzoate (1) was purchased from Sigma–Aldrich and used to synthesize compounds 2 and 3 (Scheme ) by an adaptation of the previously published procedure . All reactions were performed under dry conditions in an inert environment using distilled solvents.…”

Synthesis, characterization, and curing behavior of carborane‐containing benzoxazine resins with excellent thermal and thermo‐oxidative stability

“…Therefore, carboranes were incorporated into many traditional polymers to improve their thermal stability including polysiloxanes, epoxy resins, phenolic resins, aromatic polymers, etc. With the increasing appearance of new polymers, carboranes expanded their application fields such as dendrimers and conjugated polymers with light‐emission property …”