Thiophene is a five-membered heterocyclic compound containing a sulfur heteroatom with the molecular formula C4H4S. Thiophene is aromatic and is very similar to benzene; electrophilic substitution reaction is easier than benzene, and it is mainly substituted at the 2-position. Thiophene ring system has certain stability to oxidant.
Oxazoles are heterocyclic aromatic compounds containing one oxygen atom and one nitrogen atom, separated by a carbon atom. The presence of two heteroatoms (oxygen and nitrogen) provides possible interactions (hydrogen, hydrophobic, van der Waals or dipole bonds) with a wide range of receptors and enzymes. Oxazole rings are valuable heterocyclic scaffolds for the design of novel therapeutics with anticancer, antiviral, antibacterial, anti-inflammatory, neuroprotective, antidiabetic, and antidepressant properties due to their wide range of targets and biological activities.
Fluorene is a polycyclic aromatic hydrocarbon insoluble in water and soluble in many organic solvents. Fluorenes are one of the most important fluorescent molecules with applications in polymers, electronic devices, sensors, and photochromic materials.