The interest in studying dendrimers (repeatedly multibranched species) is based on the fact that they are inherently different from their linear analogs, and it is this constitutional difference that leads to many vivid changes in their physical properties. Unlike linear polymers, dendrimers can be prepared in a monodisperse, structurally perfect form through covalent repetitive synthesis.
Today the dendrimer research is mostly associated with their applications in diagnostics and healing, e.g., as in vivo contrast agents in X-ray and magnetic resonance imaging, as gene delivery agents, and as materials for antibodies and for repairing of corneal wounds. Their considerably large size and tunable peripheral functionality make dendrimers useful in assembling larger nano- and mesoscopic hierarchical structures that are of interest for materials science. For example, dendrimers provide an effective route to producing highly efficient phosphorescent materials which are processable from solution. Because of this utility for basic and applied science the main goal of the dendrimer synthesis has been shifted from approaching an as large as possible number of generations to the rigorous control over their shape and selective functionalization.
One of the simplest and most reliable synthetic pathways to such ‘designer’ dendrimers involves selective mono- or bis-sulfonylation of primary amines with arylsulfonyl chlorides. Repetitive sets of these reactions allow constructing selectively decorated and variably shaped dendrimers from simple building blocks at will. This synthetic approach has the advantages of a large variety of available building blocks (arylsulfonyl chlorides), quite high chemical stability of sulfonimides and convenient purification of products by recrystallization, making the production of multigram amounts straightforward. Complete or selective sulfonylation can also be used for a peripheral functionalization of commercial amine-based dendrimers, such as POPAM and PAMAM. Additional functional groups of arylsulfonyl moieties can offer many more possibilities to further elaborate the dendrimers for different applications.
Life Chemicals Building Block Collection contains over 100 functionalized arylsulfonyl chlorides which can be used for the rational design of functionally diverse dendrimers. We are offering custom synthesis of functionalized sulfonimide-based dendrimers, similar to the ones shown in Figure 1. For more structural examples see the references below.1-7 To explore synthesis options and discuss details, please, contact us at firstname.lastname@example.org.
Figure 1. Representative structures of the sulfonimide-based dendrimers and dendrons. The core and peripheral decoration are free to select.
1. Khanam, S.; Rai, S. K.; Verma, D.; Khanna, R. S.; Tewari, A. K. Advancement in The Sulfone-Based Dendrimers: From Synthesis to Application. Adv. Mater. Lett. 2017, 8, 1005–1019.
2. Kolotylo, M.; Holovatiuk, V.; Bondareva, J.; Lukin, O.; Rozhkov, V. Synthesis of sulfonimide-based dendrimers and dendrons possessing mixed 1→2 and 1→4 branching motifs. Tetrahedron Lett. 2019, 60, 352–354.
3. Lukin, O.; Gramlich, V.; Kandre, R.; Zhun, I.; Felder, T.; Schalley, C. A.; Dolgonos, G. Designer dendrimers: branched oligosulfonimides with controllable molecular architectures. J. Am. Chem. Soc. 2006, 128, 8964–8974.
4. Schubert, D.; Corda, M.; Lukin, O.; Brusilowskij, B.; Fiškin, E.; Schalley, C. A. A topological view of isomeric dendrimers. Eur. J. Org. Chem. 2008, 4148–4156.
5. Abdel-Rahman, M. A.; Schweizer, B. W.; Lukin, O.; Zhang, A.; Schlüter, A. D. Dendronized Polymers with Aromatic Sulfonimide Dendrons. Macromol. Chem. Phys. 2010, 211, 1538–1549.
6. Bergamini, G.; Ceroni, P.; Balzani, V.; Del Mar Villavieja, M.; Kandre, R.; Lukin, O. Dendrimers with a pentaphenylene core. A photophysical study. ChemPhysChem 2009, 10, 265-269.
7. Lukin, O.; Schubert, D.; Gramlich, V.; Schweizer, W. B.; Müller, C. M.; Schneider, J.; Dolgonos, G.; Shivanyuk, A. Engineering crystals of dendritic molecules. Proc. Natl Acad. Sci. USA 2009, 106, 10922-10927.