Towards Corannulene-based Synthetic Capsids
Written by Tom Mejuch
T. Mejucha, D. Pappoa, E. Solela, Y. Linkovskya, O. Reanya and E. Keinana,b,*
aThe Schulich Faculty of Chemistry and Institute of Catalysis Science and Technology, Technion – Israel Institute of Technology Technion City, Haifa 32000, Israel
bDepartment of Molecular Biology and Cell Biology, The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Recently, we have developed a general synthetic strategy for chemical capsids at an intermediate size between C60 and spherical viruses (Olson A.J, Hu Y. & Keinan E, PNAS, 2007, 104, 20731-6). The final structure could be achieved by self-assembly of symmetric pentagonal core molecules. By introducing different functional groups at the five edges of the pentagon, we wish to produce stable structures of icosahedral symmetry that can serve numerous functional roles. These structures are designed to assemble and disassemble under controlled conditions. For the core structure we have chosen corannulene, 1, a polyaromatic hydrocarbon that consists of five adjacent benzene rings to form a non-planar, cup-shaped molecule. The design and synthesis of corannulene derivatives is determined by the specific bonding mechanism, such as hydrogen bonding, electrostatic interactions, metal ligation, etc.
Improved methods for the synthesis of symmetrically functionalized corannulene derivatives was established on the basis of 1,3,5,7,9-pentachlorocorannulene, 2. These derivatives represent advanced building blocks that could lead to the desired pentagonal tiles. Transition metal catalyzed arylation, alkynylation and vinylation of 2 were examined. The Kumada, Negishi, Hyama, and Stille cross coupling reactions were tested on model reactions in order to find the most efficient method to achieve this goal.