Recent progress of direct thiocyanation reactions

Abstract

Thiocyanation can introduce SCN groups into parent molecules for constructing SCN-containing small organic molecules. In this review, we summarize the research progress of direct thiocyanation in recent years.

Visible-light-induced C(sp3)−H thiocyanation of pyrazolin-5-ones: a practical synthesis of 4-thiocyanated 5-hydroxy-1H-pyrazoles

“…Organic chemists have concentrated their efforts on exploring thiocyanation reactions and applications, which mostly involve nucleophilic substitutions, electrophilic substitutions, and free-radical thiocyanations. 2 The development of a green, sustainable, efficient, and atom economical C–S bond formation procedure is one of the most noteworthy research subjects in synthetic organic chemistry. 3 In this context, photoredox catalysis has lately appeared as a promising avenue for organic synthesis because it utilizes seemingly endless resources, such as visible light, air, and energy.…”

An environmentally benign way to synthesize 2-thiocyano-1,3-dicarbonyl compounds with high antifungal activity: a key role of solvent

“…59,[71][72][73] Electrochemical thiocyanation of C-H bonds has also made some progress, 74 especially in anodic thiocyanation of unsaturated or aromatic compounds. 57,[75][76][77][78][79][80][81][82] The few known examples of the electrochemical thiocyanation of carbonyl compounds are based on the in situ formation of α-halo ketones as the key intermediates followed by nucleophilic substitution of halogens with SCN − (Scheme 1, b). 80,83 Herein, we disclose the direct electrochemical thiocyanation of 1,3-dicarbonyl compounds in an undivided electrochemical cell via thiocyanogen generation without halogencontaining electrolytes (Scheme 1, c).…”

“…59,71–73 Electrochemical thiocyanation of C–H bonds has also made some progress, 74 especially in anodic thiocyanation of unsaturated or aromatic compounds. 57,75–82 The few known examples of the electrochemical thiocyanation of carbonyl compounds are based on the in situ formation of α-halo ketones as the key intermediates followed by nucleophilic substitution of halogens with SCN − (Scheme 1, b). 80,83…”

Regioselective C–H Thiocyanation of Arenes by Iron(III) Chloride Catalysis

“…Organothiocyanates are important compounds, found as key components of biologically active molecules and natural products . These are also used as synthetic intermediates for the preparation of various sulfur-containing organic compounds . In this regard, aryl thiocyanates are versatile building blocks for access to functionalized aromatic compounds, including medicinally important aryl trifluoromethyl thioethers. , A key approach for the synthesis of aryl thiocyanates is the cyanation of sulfur-containing arenes .…”

“…These are also used as synthetic intermediates for the preparation of various sulfur-containing organic compounds . In this regard, aryl thiocyanates are versatile building blocks for access to functionalized aromatic compounds, including medicinally important aryl trifluoromethyl thioethers. , A key approach for the synthesis of aryl thiocyanates is the cyanation of sulfur-containing arenes . This includes methods such as the copper-catalyzed cyanation of disulfides with azobisisobutyronitile and the direct photocatalytic cyanation of aryl thiols by cleavage of the C–S bond of ammonium thiocyanate .…”