For almost 20 years, thioureas have been experiencing a renaissance of interest with the emerged development of asymmetric organocatalysts. Due to their relatively high acidity and strong hydrogen bond donor capability, they differ significantly from ureas and offer, appropriately modified, great potential as organocatalysts, chelators, drug candidates, etc. The review focuses on the family of chiral thioureas, presenting an overview of the current state of knowledge on their synthesis and selected applications in stereoselective synthesis and drug development.

A library of 21 novel chiral 1,2,3-triazole-based 2-azabicycloalkane conjugates was designed and synthesized using the copper(I)-catalyzed click reaction. The obtained hybrids were assessed for their antiproliferative potency against three selected human cancer cell lines: Hs294T (melanoma), MIA PaCa-2 (pancreas tumor) and NCI-H1581 (lung tumor). The majority of the synthesized compounds demonstrated moderate to potent activity, and some of them appeared more selective than cisplatin, with selectivity index exceeding 9.

Organocatalysis is a very useful tool for the asymmetric synthesis of biologically or pharmacologically active compounds because it avoids the use of noxious metals, which are difficult to eliminate from the target products. Moreover, in many cases, the organocatalysed reactions can be performed in benign solvents and do not require anhydrous conditions. It is well-known that most of the above-mentioned reactions are promoted by a simple aminoacid, l-proline, or, to a lesser extent, by the more complex cinchona alkaloids. However, during the past three decades, other enantiopure natural compounds, the carbohydrates, have been employed as organocatalysts. In the present exhaustive review, the detailed preparation of all the sugar-based organocatalysts as well as their catalytic properties are described.