Dimere Isothiocyanate von Kohlensäureestern und einem Thiokohlensäure‐S‐ester

Abstract

Dimeric Isothiocyanates of Carbonic Esters and a Thiocarbonic S‐Ester The isothiocyanates 1 dimerize at low temperature and with a catalytic amount of base to form the crystalline dithietane derivatives 2.

Rearrangements of Acyl, Thioacyl, and Imidoyl (Thio)cyanates to Iso(thio)cyanates, Acyl Iso(thio)cyanates to (Thio)acyl Isocyanates, and Imidoyl Iso(thio)cyanates to (Thio)acyl Carbodiimides, RCX-YCN ⇌ RCX-NCY ⇌ RCY-NCX ⇌ RCY-XCN (X and Y = O, S, NR′)

“…Ethoxycarbonyl thiocyanate is a distillable compound (41–42 °C/2 mmHg), but the corresponding (ethylthio)­carbonyl thiocyanate was not isolable under similar reaction conditions. , Goerdeler and Chuen-Huei Ho also found that only the isothiocyanates RS–CO–NCS were obtainable from the acyl chlorides and NaSCN . However, we calculate very similar activation barriers for the isomerization of the two compounds, 42 and 40 kcal/mol, respectively (Scheme ).…”

A Novel One-pot Synthesis of Isothiocyanates and Cyanamides from Dithiocarbamate Salts Using Environmentally Benign Reagent Tetrapropylammonium Tribromide

“…4 Numerous methods for the preparation of isothiocyanates have been reported, starting from amines, 5 dithiocarbamates, 6 organic halides, 7 olefins 8 and aldoximes. 9 Among the literature methods, the most widely used procedure is the synthesis by the decomposition of dithiocarbamates using heavy metals, 10 thiophosgene, iodine, ethylchlorocarbamate and claycop. 11 Although many synthetic methods for the preparation of isothiocyanates have been reported to date, most methods suffer from the employment of highly toxic reagents.…”

A One-pot Preparation of Isothiocyanates from Amines Using Two Phosgene Substitutes: Bis-(trichloromethyl) Carbonate and Trichloromethyl Chloroformates

“…4 Numerous methods for the preparation of isothiocyanates have been reported from amines, 5 dithiocarbamates, 6 organic halides, 7 olefins 8 and aldoximes. 9 Among the literature methods, the most widely used procedure is for their synthesis by the decomposition of dithiocarbamates using heavy metals, 10 thiophosgene iodine, ethyl chlorocarbonate and claycop. 11 However, most of the methods suffer from low yields and the use of environmentally unattractive reagents.…”

“…11 However, most of the methods suffer from low yields and the use of environmentally unattractive reagents. 10 Bis-trichloromethyl carbonate (BTC) and trichloromethyl chloroformate (TCF) have emerged as versatile synthetic reagents and as important substitutes for phosgene in the synthesis of some important classes of organic compounds. 12 Both of them are more convenient to handle and store than phosgene, due to their low vapour pressure being in the liquid and the solid states.…”