Sulfoxides constitute one of the most important functional groups in organic chemistry found in numerous pharmaceuticals and natural products. Sulfoxides are usually obtained from the oxidation of the corresponding sulfides. Among various oxidants, oxygen or air are considered the greenest and most sustainable reagent. Photochemistry and photocatalysis is increasingly applied in new, as well as traditional, yet demanding, reaction, like the aerobic oxidation of sulfides to sulfoxides, since photocatalysis has provided the means to access them in mild and effective ways. In this review, we will summarize the photochemical protocols that have been developed for the oxidation of sulfides to sulfoxides, employing air or oxygen as the oxidant. The aim of this review is to present: i) a historical overview, ii) the key mechanistic studies and proposed mechanisms and iii) categorize the different catalytic systems in literature.Scheme 2. Traditional sulfide oxidation methods. Scheme 3. Sulfide oxidation methods utilizing oxygen as the oxidant.

Since United Nations has set goals dealing with climate change, the chemical industry has focused on recycling the already-used polymers, targeting the reinsertion of plastic waste to market via new...

The sulfoxide moiety is recognized as one of the most important groups in organic and medicinal chemistry. Many efforts worldwide focus on developing novel and sustainable protocols, accessing sulfoxide-containing molecules....

A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.

Dedicated to Prof. Panagiota Moutevelis-Minakakis on the occasion of her retirement. An efficient, green, cheap, and metal-free photochemical protocol for the synthesis of benzimidazoles has been developed. 2,2-Dimethoxy-2-phenylacetophenone was employed as the photoinitiator and CFL lamps were used as the light source, leading to the cyclization of substituted diamines with aldehydes. The corresponding benzimidazoles were obtained in good to high yields. Mechanistic studies were conducted, in order to determine a plausible mechanism for the reaction.