Click Reaction of Selenols with Isocyanates: Rapid Access to Selenocarbamates as Peroxide‐Switchable Reservoir of Thiol‐Peroxidase‐Like Catalysts

Abstract

Selenols react with isocyanates under mild catalyst-free conditions to generate selenocarbamates in good yield and with high selectivity over potentially competing nucleophilic additions. The methodology enables the incorporation of a wide variety of functional groups providing access to a broad array of densely functionalised selenocarbamates. In the presence of competing heteroatom-centered nucleophiles, isocyanates selectively couple with selenols. Selenocarbamates exhibited thiol-peroxidase-like properties, enabling the reduction of hydrogen peroxide at the expense of thiols, which are converted into the corresponding disulfides. A series of control experiments suggested that the catalytic mechanism proceeds through a pathway, involving a H 2 O 2 -promoted transcarbamoylation reaction leading to a thiocarbamate with concomitant releasing of catalytically active selenolate anions. By undergoing peroxide-driven thiol-selenol exchange, selenocarbamates behave as equivalents of selenolate anions with thiol-peroxidase-like activity.

The Role of Selenium in Pathologies: An Updated Review

“…A number of selenium-containing molecules also exhibited remarkable carbonic anhydrase inhibitor activity against different pathogenic bacteria, including Vibrio cholera , Burkholderia pseudomallei , and Mycobacterium tuberculosis [ 40 ]. Over the past years, the synthesis and the study of synthetic or semi-synthetic selenium-containing derivatives has attracted a steadily growing interest amongst organic chemists, medicinal chemists, and biologists [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ].…”

Synthesis of Nitroarenes by Oxidation of Aryl Amines

“…For example, selenium-catalysed routes for the oxidation of organic compounds including, among others, alkenes [50][51][52], alcohols [50,53], alkynes [50], and carbonyl derivatives [50] have been developed. Additionally, biologically relevant selenium-catalysed thiol-disulfide interconversions have been widely investigated over the past few years [54][55][56][57][58][59][60][61].…”

Synthesis and Applications of Organic Selenols

“…Notably, selenocarbamates bearing hydroxy‐ and amino‐ functionalities 63 l – o were efficiently obtained through the selective carbamoylation of the SeH group (Scheme 31). [84] Selenocarbamates exhibit remarkable thiol‐peroxidase‐like catalytic properties. Studies on the reaction mechanism suggested an unprecedented path involving a peroxide‐driven transcarbamoylation reaction engendering catalytically active selenolate anions.…”

“…Studies on the reaction mechanism suggested an unprecedented path involving a peroxide‐driven transcarbamoylation reaction engendering catalytically active selenolate anions. Therefore, because of the reactivity of their selenium‐carbon bond, selenocarbamates act as unconventional equivalents of selenolate anions [84] …”

“…Therefore, because of the reactivity of their selenium-carbon bond, selenocarbamates act as unconventional equivalents of selenolate anions. [84] Selenols efficiently react with electron-poor alkenes providing access to the corresponding seleno-Michael adducts. Owing to the nucleophilicity of the selenol moiety such a conjugate addition can be performed under mild conditions, thus enabling the selective Se- functionalisation of substrates bearing potentially competing nucleophiles.…”