Organosulfur compounds are common in the pharmaceutical industry. Recent reports estimate that in 2012 about 20% of all pharmaceuticals were organosulfur compounds.1 Therefore, many methods have been developed to incorporate sulfur into organic compounds.
Recently, Tiwari’s group reported a transition-metal-free construction of 3-ketoquinolines from readily-available acetophenones and anthranils (Equation 1).1 This method employs DMSO as a solvent and a one carbon source to complete the quinoline carbon skeleton.
Visible light promoted reactions using photosensitizers are rapidly being developed.1 These reactions use visible light as a renewable energy source and a photosensitizer, often eliminating the need for harsh reaction conditions. DMSO is often the solvent of choice for these types of reactions.2
Phenols are widely used in synthetic schemes, and they occur in many natural products and medicinally-useful compounds. Nevertheless, there are only a limited number of methods available to produce the phenolic group from readily available haloarenes.
The list of useful, high-yielding, environmentally-friendly, and inexpensive reactions catalyzed by DMSO/I2 continues to grow (for previous examples, see Synthesis Post articles from March 2017 and June, July, and October 2016).
The development of methods to functionalize imidazo[1,2-α]pyridines is an area of interest due to the frequency of this structural unit in pharmaceutical compounds and functional materials.
Ravikumar and coworkers have developed a new chemoselective oxidation method using DMSO as the oxidant
A recent Synthesis Corner post reviewed work where cyclohexanones acted as convenient starting materials for the synthesis of aromatic compounds through a DMSO/I2 catalyzed route.
Jiao, et al., have recently reported an attractive method to make substituted catechols from cyclohexanones using the simple, mild, metal-free and inexpensive DMSO/I2 catalytic system (Equation 1).
The inherent low toxicity of DMSO and its ability to solubilize a variety of species often makes it the best solvent for these light-induced reactions.