Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• most effective solvents for gold [20]. Because of the high toxicity and strong environmental impact of cyanides, eco-friendlier alternatives are currently under research. Some are based on replacing cyanide with less harmful chemicals, such as thiocyanate, thiourea, or thiosulfate. Another alternative

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• ). Although using other solvents improved the solubility, it reduced the reaction yield. Ammonium thiocyanate is used as a sulfur source in the presence of DBU as a base and n-Bu4NBF4 as an electrolyte. When electron-donating groups were present at the C2-benzene ring, the reaction yield was higher than when

• the rings contained electron-withdrawing groups. It is suggested that the reaction proceeded via single-electron oxidation of thiocyanate at the anode. DBU was used in the reaction for a simple nucleophilic substitution of phosphonate with a cyanide group in the formed intermediate (Scheme 28). In

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• significantly lower yields of 3aa (Table 1, entry 2). Replacing the Cu(TFA)2 catalyst with other copper sources, such as cuprous chloride (CuCl), cuprous thiocyanate (CuSCN), copper bromide (CuBr2), copper trifluoromethanesulfonate (Cu(OTf)2), and copper powder resulted in diminished reaction efficiency (Table

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• direct C(sp2)–H functionalization of aldehyde-derived N,N-dialkylhydrazones has been also explored for constructing various azacycles. In 2021, the group of Ruan and Feng studied the electrochemical C(sp2)–H thiocyanation of aldehyde-derived N,N-dialkylhydrazones 95 with sodium thiocyanate (96) to

• of aromatic aldehyde-derived hydrazones regardless of their electronic properties as well as aliphatic-aldehyde derived hydrazones. Cyclic voltammetry analysis showed that thiocyanate salt 96 possesses a lower oxidation potential than the hydrazone 95. As such, the authors proposed the anodic

• generation of electrophilic thiocyanogen as the initial step. Further reaction with the hydrazone 95 and deprotonation led to hydrazonoyl thiocyanate intermediate 99, which isomerized to the thermodynamically more stable isothiocyanate derivatives 100 through 1,3-shift. The latter underwent spontaneous ring

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• hypervalent fluoroiodane reagents [92][93]. In 2000, Fuchigami and co-workers demonstrated the effectiveness of these reagents in the oxidative electrochemical fluorination of benzylic positions adjacent to thiocyanate groups (Figure 36) [94]. The authors proposed anodic oxidation to generate a radical cation

• that can undergo facile α-proton elimination facilitated by the strongly electron-withdrawing thiocyanate group. Subsequent anodic oxidation affords a cationic species that can be trapped by fluoride to afford the product. This reaction was demonstrated on four substrates in yields of 47–71%. The

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• ][44][45]. However, the electrophilic thiocyanation of biologically important pyrazoles has been less explored [46][47][48]. Among them, the majority of the reported methods proceed through a radical pathway, with the SCN radical generated by the reaction of the thiocyanate source with a corresponding

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• ) [39][40], and two thiocyanate ligands. As observed for other cobalt complexes [21], the photoinduced CO2 reduction gave preferentially molecular hydrogen, when performed in acetonitrile. Moreover, we targeted a photocatalytic system that is fully earth-abundant. For this reason, we selected the known

• catalytic current was observed at the onset potential of −1.4 V. Although a direct comparison between Co(II) and Fe(II) ions cannot be made, it is reasonable to suggest that after the first reduction a −NCS ligand detaches and an adduct with CO2 is formed, as it was calculated for a similar thiocyanate

• ·) and after the addition of two protons, CO and H2O are produced. The cycle could be closed by the coordination of thiocyanate to the cationic Co(II) species, which is left after the generation of the products, or maybe the reduction of the above-mentioned species occurs with another PS cycle. This

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• accordion porphyrins with various linkers [54][125]. Their formation typically relied on a template synthesis approach [126][127]. The first reported accordion porphyrin was synthesised as a binucleated lead(II) complex 13 (Scheme 4) [52]. The reaction of diformyldipyrromethane 12, lead(II) thiocyanate, and

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• , the authors noted the reaction was stereoselective for the trans-addition product. Mechanistically, the authors proposed the reaction begins with the Cu-mediated substitution reaction of iodobenzene (66a) with KSCN to afford phenyl thiocyanate (70). The Cu complex can then undergo oxidative addition

• into the S–C bond of the thiocyanate 70 to afford intermediate 71 which can side-on coordinate to the exo face of 30b. Subsequently, the thiocyanate attacks the olefin from the endo face via 72 to give complex 73. Reductive elimination furnishes the final difunctionalized product and regenerates the

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• thiocyanate to generate 4-alkyl/aryl-2-aminothiazoles. Mechanistic experiments demonstrated that the photocatalyst formed in situ from Cu(OAc)2 and ammonium thiocyanate promoted the intermolecular cyclization (Scheme 7). 3.2 Difunctionalization of alkenes The 1,2-difunctionalization of alkenes is a versatile

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate

• Mysore Bhyrappa Harisha,
• Pandi Dhanalakshmi,
• Rajendran Suresh,
• Raju Ranjith Kumar and
• Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178

• azidochalcones, when treated with potassium thiocyanate in the presence of potassium persulfate, lead to 2,4,5-trisubstituted oxazoles in good yields. Incidentally, 2-aminothiazoles are the products when ferric nitrate is employed instead of persulfate in the above reaction. Keywords: aminothiazole; oxazole

• substituted α-azidochalcones with potassium thiocyanate. Thiocyanate is a known ambident reagent with two potential sites of attack, enabling the selective and efficient construction of C–C and C–N bonds towards biologically important heterocyclic skeletons [62][63][64]. Results and Discussion Previously, we

• with a highly substituted oxazole skeleton with a thiol group is expected to have potential synergetic bioactivity [70]. During the exploration of the reactivity of azidochalcones with thiocyanate in the presence of the oxidizing agent, 1i was chosen as the model α-azidochalcone to react with potassium

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• the same kind of substrates, 6-thiocyanatophenanthridines were isolated in discrete to excellent yields, in the presence of ammonium thiocyanate (NH4SCN) as the thiolating agent [68]. A very peculiar case is that described in Scheme 8 for the synthesis of 6-(trifluoromethyl)-7,8-dihydrobenzo[k

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• thiocyanate anion both play specific roles in the generation of an active Cu species able to trap the Si–Li (previously formed by reaction of LiO-t-Bu(THF)3 with PhMe2Si-Bpin; other atoms on Si and Li were omitted for clarity). The resultant Cu–Si species may then form a dative bond with the alkyl iodide

Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

• Svetlana V. Amosova,
• Andrey A. Filippov,
• Nataliya A. Makhaeva,
• Alexander I. Albanov and
• Vladimir A. Potapov

Beilstein J. Org. Chem. 2020, 16, 515–523, doi:10.3762/bjoc.16.47

• proceeding at the C2 carbon atom of the seleniranium cation 2 with dithiocarbomates [31], thiourea [32], alcohols [42], functionalized organic acids [43][44], functionalized pyridines [45], ammonium thiocyanate [46], and mercapto benzazoles [40] were developed (Scheme 4). The new methodology of a

• with various nucleophiles (Scheme 4) were accompanied by ring expansion leading to six-membered functionalized dihydrothiaselenines. Furthermore, the reaction of thiaselenole 1 with ammonium thiocyanate also gave the six-membered 2,3-dihydro-1,4-thiaselenin-2-yl thiocyanate (Scheme 4) [46]. It was

Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

• Clément Ghiazza and
• Anis Tlili

Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30

• moieties. One year later, the group of Goossen demonstrated the direct conversion of diazo compounds into trifluoromethylselenolated products using a catalytic amount of copper(I) thiocyanate (Scheme 11) [28][29]. The reaction proceeded under mild conditions, and the desired products were usually obtained

The use of isoxazoline and isoxazole scaffolding in the design of novel thiourea and amide liquid-crystalline compounds

• Itamar L. Gonçalves,
• Rafaela R. da Rosa,
• Vera L. Eifler-Lima and
• Aloir A. Merlo

Beilstein J. Org. Chem. 2020, 16, 175–184, doi:10.3762/bjoc.16.20

• were synthetized and the liquid crystal properties studied. Thioureas were obtained using a condensation reaction of benzoyl chlorides, arylamines and ammonium thiocyanate. The amides, on the other hand, were the byproduct of a quantitative reaction which used potassium cyanate as the starting material

• this group of molecules, numerous strategies have been developed for their preparation. Substituted thioureas can be obtained using a variety of approaches although the simplest route involves the heating of ammonium thiocyanate with an amine in an aqueous acid medium [5]. They can also be synthesized

• in the reaction of thiourea with primary amines [6]. Another important synthetic route for substituted thioureas is a two-step approach: (i) the addition/elimination reaction of benzoyl chloride, with a thiocyanate salt, generating in situ, benzoyl isothiocyanate, and (ii) an appropriate amine

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

• Narasimhamurthy Rajeev,
• Toreshettahally R. Swaroop,
• Ahmad I. Alrawashdeh,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Seegehalli M. Anil,
• Kuppalli R. Kiran,
• Chandra,
• Paris E. Georghiou,
• Kanchugarakoppal S. Rangappa and
• Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

• of xanthate esters with amines [18]. Furthermore, many methods have also been reported for the synthesis of cyclic thiocarbamates, and these include reactions of isothiocyanates with aldehydes in the presence of organocatalysts [19][20], reactions of vicinal diols with potassium thiocyanate [21

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• M of LiI, 0.1 M of guanidinium thiocyanate in a mixture of acetonitrile and 3-methoxyproprionitrile (85:15). Compared to classical electrolytes, in this formulation we removed tBP, hoping that the suppression of the interface dipole would shift the CB energy level of TiO2 and, consequently, enhance

• −2, electrolyte composition: 0.5 M of BMII, 0.03 M of I2, 0.5 M of LiI, 0.1 M of guanidinium thiocyanate in a mixture of acetonitrile and 3-methoxyproprionitrile (85:15, v/v), electrodes: 12 µm mesoporous anatase TiO2 + 4 µm TiO2 scattering layer, dyeing bath: [Dye] = 0.2 mM, [CDCA] = 2 mM in CHCl3

• composition: 0.5 M of BMII, 0.03 M of I2, 0.5 M of LiI, 0.1 M of guanidinium thiocyanate in a mixture of acetonitrile and 3-methoxyproprionitrile (85:15, v/v), electrodes: 12 µm mesoporous anatase TiO2, + 4 µm TiO2 scattering layer, dyeing bath: [Dye] = 0.2 mM, [CDCA] = 2 mM in CHCl3/EtOH 1:1, v/v). Highest

A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

• András György Németh,
• György Miklós Keserű and
• Péter Ábrányi-Balogh

Beilstein J. Org. Chem. 2019, 15, 1523–1533, doi:10.3762/bjoc.15.155

• based on the reaction of amines and the readily available, but toxic and volatile carbon disulfide [42][43][44][45]. Greener methods for the synthesis of thiocarbamates and dithiocarbamates have been developed such as the addition of the amine component to potassium thiocyanate [46][47] or

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• compatibility. Hajra et al. have reported the direct C–H thiocyanation of substituted imidazo[1,2-a]pyridines, using ammonium thiocyanate, in combination with Eosin Y under irradiation by blue LEDs (Scheme 9) [52]. This is another photoredox example of C–S bond formation, in this case to a highly versatile

• thiocyanate functional group, which is a precursor group to many sulfur-containing functional groups, as well as heterocycles such as thiazoles and isothiazoles. The imidazo[1,2-a]pyridine core is a particularly interesting drug-like structure, e.g., electron poor, polar, of low basicity, etc. The scope of

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• -methoxy-3-thiocyanatobenzene (1f), prepared from 1-ethyl-4-methoxybenzene (1a) through the hypervalent iodine(III)-induced aromatic cation radical coupling with thiocyanate [75][76], similarly acetoxylated under the standard reaction conditions without zinc(II) acetate (Table 2, entry 5). The