ABSTRACT
Thiols are important precursors for the synthesis of a variety of pharmaceutically important sulfur-containing compounds. In view of the versatile reactivity of free thiols, here we report the development of a visible light-mediated direct decarboxylative thiolation reaction of alkyl redox-active esters to free thiols based on the abundant carboxylic acid feedstock. This transformation is applicable to various carboxylic acids, including primary, secondary, and tertiary acids as well as natural products and drugs, forging a general and facile access to free thiols with diverse structures. Moreover, the direct access to free thiols affords an advantage of rapid in situ diversification with high efficiency to other important thiol derivatives such as sulfide, disulfide, thiocyanide, thioselenide, etc.
Subject(s)
Sulfhydryl Compounds/chemistry , Sulfhydryl Compounds/chemical synthesis , Drug Discovery , Esters/chemical synthesis , Esters/chemistry , Models, Chemical , Molecular Structure , Oxidation-Reduction , Protein Processing, Post-Translational , Small Molecule LibrariesABSTRACT
Thioesters and related thiols are critically important to biological systems and also widely employed in the synthesis of pharmaceutically important molecules and polymeric materials. However, known synthetic methods often suffer from the disadvantage of being specific only to certain substrates. Herein, we describe a facile decarboxylative thioesterification of alkyl acid derived redox-active esters by merging photoredox catalysis and copper catalysis. This reaction is applicable to a wide range of carboxylic acids, as well as natural products and drugs, allowing for the synthesis of various thioesters with diverse structures, including tertiary ones that are not accessible via traditional nucleophilic substitution from tertiary halides. Moreover, product utilization is demonstrated with a direct transformation of thioesters to sulfonyl fluorides.
ABSTRACT
A visible light-mediated, metal-free dehydrosulfurization reaction of thioamides to nitriles is described. This reaction features high yields, mild reaction conditions, and the use of a cheap organic dye as the photoredox catalyst and air as the oxidant.
ABSTRACT
A visible-light-mediated deaminative thioesterification of amino acid derived Katritzky salts with thiobenzoic acid has been developed, which provides a novel synthetic method for the synthesis of α-mercapto acid derivatives under mild conditions. This photoredox catalyst-free generation of alkyl radicals via C-N bond cleavage is enabled by the formation of an electron-donor-acceptor (EDA) complex between the Katritzky salt and thiobenzoic acid anion, which represents a new entry for EDA complex chemistry.
Subject(s)
Amino Acids/chemistry , Light , Photochemical Processes , Salts/chemistry , Amines/chemistry , Benzoic Acid/chemistry , Electron Transport , EsterificationABSTRACT
The past few years have witnessed a fast-growing research interest on the study of sulfonyl fluorides as reactive probes in chemical biology and molecular pharmacology, which raises an urgent need for the development of effective synthetic methods to expand the toolkit. Herein, we present the invention of a facile and general approach for the synthesis of aliphatic sulfonyl fluorides via visible-light-mediated decarboxylative fluorosulfonylethylation. The method is based on abundant carboxylic acid feed stock, applicable to various alkyl carboxylic acids including primary, secondary, and tertiary acids, and is also suitable for the modification of natural products like amino acids, peptides, as well as drugs, forging a rapid, metal-free approach to build sulfonyl fluoride compound libraries of considerable structural diversity. Further diversification of the SO2F-containing products is also demonstrated, which allows for access to a range of pharmaceutically important motifs such as sultam, sulfonate, and sulfonamide.
