The first attempts of microvawe-assisted (MW) syntheses of bile acid derivatives were performed in domestic MW appliances. However, the reproducibility of these syntheses, performed in uncontrolled conditions, was very low. In first part of the presented overview compounds synthesized in such conditions are presented. Consequently with the development of MW technology, MW-assisted reactions in the MW reactors became reproducible, so in second part of this review syntheses of bile acids-based compounds in MW reactors are presented. Among others, here are reviewed, according to the existing literature:
- Chemical transformations of hydroxyl and/or carboxyl functions of bile acids into ester or amides,
- Hydroxyl groups oxidation,
- Derivatization of oxo-compounds with different nitrogen-containing compounds (eg. 4-amino-3-substituted-1H-1,2,4-triazole-5-thiones, thiocarbohydrazides and thiosemicarbazides)
- Bile acid-based molecular tweezers, capable for stereospecific molecular recognition
- Reactions of hydroxyl functions to give chlorine derivatives, presenting reactive intermediates in the substitution reactions with N- or O-containing nucleophilic arylhydrazides, urea derivatives, substituted thiadiazoles or triazoles or amino acid methyl esters, mainly in solvent-free conditions.
Some of the synthesized compounds expressed antimicrobial potential and/or good recognition properties as artificial receptors for some amino acids or anions.
Detailed comparisons between the conventional and MW-assisted procedures of chemical transformations of bile acids are given in most of presented publications. According to them, MW irradiation methods are simpler, more efficient, cleaner and faster synthetic methods and that, accordingly, greatly fit the requirements of green chemistry.