Peroxodisulfate-assisted three-component benzylation of coumarins with styrenes and KSCN: a transition-metal-free approach for the synthesis of 3-(1-aryl-2-thiocyanatoethyl)-2H-chromen-2-one in ethyl lactate

Abstract

The peroxodisulfate-assisted three-component benzylation of coumarins with styrenes and KSCN to 3-(1-aryl-2-thiocyanatoethyl)-2H-chromen-2-one is reported for the first time. This reaction proceeds via the consecutive addition of SCN radical to styrenes...

Radical Thiocyano(Selenocyano)trifluoromethylations of Alkenes on Water

“…Firstly, tetrazole 74 was synthesized through Click reaction of 1 and NaN 3 (Scheme 3A). Then, thiolate 75 was obtained by treating 1 with Ph 2 P(O)H for 2 h in the presence of DBU in toluene at room temperature (Scheme 3B) [14] . Finally, the hydrolysis of 1 afforded thiocarbamate 76 under acidic conditions (Scheme 8C).…”

“…Experimental procedures, compounds characterization data, and NMR spectra for all unknown compounds. Additional references cited within the Supporting Information [5a,c,7a,b,13b,c,14] …”

Photo-induced spirocyclization of biaryl ynones with ammonium thiocyanate: access to thiocyanate-featured spiro[5,5]trienones

“…To date, various efficient protocols for the construction of aryl, alkyl, or vinyl thiocyanates have been developed by many chemists. 6–9 Among them, as valuable organic substrates, vinyl thiocyanates are commonly produced from alkenes, alkynes, or their derivatives via coupling/addition/cascade reactions (Scheme 1a). 8,9 Recently, our group reported a photo-promoted tandem cyclization of ammonium thiocyanate (NH 4 SCN) with aryl acetylenes to access seven-membered exocyclic vinyl thiocyanates (Scheme 1b).…”

Photoredox-Catalyzed Redox-Neutral Decarboxylative C–H Acylations of Coumarins with α-Keto Acid

“…These privileged scaffolds are widely present in pharmaceutical compounds and possess significant biological activities such as anticancer, anti-HIV, antimicrobial, antifungal, antioxidant, anti-inflammatory, and anticoagulant activities. − Therefore, chemists have spent a great deal of effort to develop powerful and reliable methods for the synthesis of coumarin derivatives. A quick survey of the literature highlights various synthetic methods for functionalization of coumarin at position C-3 by transition metal catalysis or photocatalysis. − Though a huge amount of progress has been achieved in C-3 functionalization, − after decades of research, practical methods for the functionalization of coumarin at position C-4 are still lacking. Among the well-known procedures, palladium-catalyzed cross-coupling and nickel-catalyzed cross-coupling were regarded as two of the predominant approaches. , Wu and Yang described nickel-catalyzed cross-coupling of 4-diethylphosphonooxycoumarins with organozinc bromides to give 4-substituted coumarins (Scheme a) .…”