Efficient synthesis of selenol esters from acid chlorides mediated by indium metal

Palladium-Catalyzed Carbonylative Synthesis of Aryl Selenoesters Using Formic Acid as an Ex Situ CO Source

A new catalytic protocol for the synthesis of selenoesters from aryl iodides and diaryl diselenides has been developed, where formic acid was employed as an efficient, low-cost, and safe substitute for toxic and gaseous CO. This protocol presents a high functional group tolerance, providing access to a large family of selenoesters in high yields (up to 97%) while operating under mild reaction conditions, and avoids the use of selenol which is difficult to manipulate, easily oxidizes, and has a bad odor. Additionally, this method can be efficiently extended to the synthesis of thioesters with moderate-to-excellent yields, by employing for the first time diorganyl disulfides as precursors.

Synthetic Approaches to Selenoesters

Selenoesters are compounds of great synthetic relevance since they can be used in several types of chemical transformations and mainly due to their great capacity in the formation of acyl radicals. Therefore, the scientific community has been developing several methods for the synthesis of this class of molecules. This review will address the synthesis of these compounds from different starting materials, such as carboxylic acids derivatives (acid chlorides and anhydrides), aldehydes, selenoacetylenes and miscellaneous methods.

Redox-Neutral Synthesis of Selenoesters by Oxyarylation of Selenoalkynes under Mild Conditions

An approach for the mild synthesis of selenoesters starting from selenoalkynes through an acid-catalyzed, redox-neutral oxyarylation reaction is reported. Brønsted acid activation of a selenoalkyne leads to a selenium-stabilized vinyl cation, which is captured by an aryl sulfoxide and undergoes sigmatropic rearrangement to deliver the final α-arylated selenoester product. Computational studies have been carried out to elucidate the nature of the Se-stabilized carbocation.

Atom Efficient Preparation of Zinc Selenates for the Synthesis of Selenol Esters under "On Water" Conditions

We describe here an atom efficient procedure to prepare selenol esters in good to excellent yields by reacting [(PhSe)₂Zn] or [(PhSe)₂Zn]TMEDA with acyl chlorides under "on water" conditions. The method is applicable to a series of aromatic and aliphatic acyl chlorides and tolerates the presence of other functionalities in the starting material.

General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis

A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.

Polyethylene glycol-400/H3PO2: an eco-friendly reductive system for the synthesis of selanylesters

An alternative green method was described for the synthesis of selanylesters by reactions of acyl chlorides with arylselenols, generated in situ by reaction of diaryl diselenides with hypophosphorous acid (H₃PO₂) using polyethylene glycol-400 (PEG-400) as the solvent.

Experimental and DFT study on the indium-mediated synthesis of benzophenones via arylstannanes

A DFT analysis was performed with the aim to explaining the narrow scope of the indium-promoted reaction of aroyl chlorides with arylstannanes.

Syntheses of selenoesters through C–H selenation of aldehydes with diselenides under metal-free and solvent-free conditions

A DTBP-promoted C–H selenation of aldehydes with diselenides under metal-free and solvent-free conditions is described.

Syntheses of thiol and selenol esters by oxidative coupling reaction of aldehydes with RYYR (Y = S, Se) under metal-free conditions

Thiol (selenol) esters were synthesized by a direct oxidative coupling reaction of aldehydes with disulfides (diselenides) under metal-free conditions.

“The green side of the moon: ecofriendly aspects of organoselenium chemistry”

Key aspects for the development of a greener synthesis and the use of the organoselenium compounds.

Reduction cleavage of S–S bond by Zn/Cp2TiCl2: Application for the synthesis of β-arylthiocarbonyl compounds

Diaryl disulfides were reduced efficiently by a Zn/Cp2TiCl2 system at room temperature in dry THF to give the corresponding nucleophilic sulfur anion–titanocene complex, followed by reaction with α, β-unsaturated esters (ketones or nitriles) to afford the corresponding β-arylthioesters(ketone or nitrile) in good yields.