Ammonium metavanadate/thiocyanate-triggered electrophilic thiocyanation of aromatic and heteroaromatic compounds in aqueous bisulfate and acetonitrile media

Nitrogen Dioxide Catalyzed Oxidative Thiocyanation of Arenes with Ambient Air as the Terminal Oxidant

“…Pale yellow solid; m.p. 71–72 °C (lit . 72–74 °C); 1 H NMR (500 MHz, CDCl 3 ): δ =7.44 (d, 3 J H−H =9.0 Hz, 2 H, Ph), 6.70 (d, 3 J H−H =9.0 Hz, 2 H; Ph), 3.02 ppm (s, 6 H, CH 3 ); 13 C NMR (500 MHz, CDCl 3 ): δ =151.7, 134.5, 113.2, 112.6, 106.5, 40.2 ppm.…”

“…Pale yellow solid; m.p. 104–106 °C (lit . 105–107 °C); 1 H NMR (500 MHz, CDCl 3 ): δ =8.35 (d, 3 J H−H =8.4 Hz, 1 H), 8.29 (d, 3 J H−H =8.5 Hz, 1 H), 7.86 (dd, 3 J H−H =8.2 Hz, 1 H), 7.73 (t, 3 J H−H =7.4 Hz, 1 H), 7.62 (t, 3 J H−H =7.8 Hz, 1 H), 6.82 (dd, 3 J H−H =8.2 Hz, 1 H), 4.04 ppm (d, 5 J H−H =1.5 Hz, 3 H); 13 C NMR (500 MHz, CDCl 3 ): δ =158.7, 135.3, 133.7, 128.7, 126.8, 126.4, 124.6, 123.1, 111.5, 110.4, 104.1, 55.0 ppm.…”

“…However, SCN − is unreactive towards aromatic rings . An effective solution to this is the use of the oxidative strategy in which either SCN − or aromatic rings are oxidized in situ to the reactive species in the presence of various oxidants, for example, H 2 O 2 , K 2 S 2 O 8 , cyanuric chloride, oxone, NaClO 4 , 2,3‐dichloro‐5,6‐dicyanobenzoquinone, NH 4 VO 3 , and silica‐bonded vanadic acid …”

“…However,S CN À is unreactive towards aromatic rings. [1b] An effective solution to this is the use of the oxidative strategy [1b] in which either SCN À or aromatic rings are oxidized in situ to the reactive species in the presenceo fv arious oxidants, for example, H 2 O 2 , [5] K 2 S 2 O 8 , [6] cyanuric chloride, [4a] oxone, [7] NaClO 4 , [8] 2,3-dichloro-5,6-dicyanobenzoquinone, [9] NH 4 VO 3 , [10] and silicabondedv anadic acid. [11] Compared with the oxidants mentioned above,O 2 ,e specially air,i sabetter oxidant because it is inexpensive, readily available, and environmentally friendly,w hich has prompted many chemists to apply O 2 in the oxidation of organic substrates under the catalysis of various transition metals.…”

Quinolinium bound chromium(VI) reagents for efficient electrophilic aromatic nitration and thiocyanation reactions using sodium nitrate and ammonium thiocyanate

“…The unspent acids left out in these protocols often cause environmental pollution. In recent years, several new approaches have been developed to control the regiochemistry of the reactions [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”