Cerium ammonium nitrate-catalyzed aerobic oxidative coupling of dithiocarbamates: facile synthesis of thioureas and bis(aminothiocarbonyl)disulfides
作者:Tian-Tian Li、Xiang-Hai Song、Mei-Shuang Wang、Ning Ma
DOI:10.1039/c4ra04628e
日期:——
Diverse disubstituted and trisubstituted thioureas were synthesized by the condensation of dithiocarbamate TEA (or DABCO) salts and amines using cerium ammonium nitrate (CAN) as a catalyst in high yields at room temperature. It is a one-pot method and it is unnecessary to isolate isothiocyanates. This reaction probably took place through nucleophilic addition of amines to isothiocyanates, which were generated by oxidative coupling of dithiocarbamates and the following decomposition of bis(aminothiocarbonyl)disulfides. When secondary amines and CS2 served as the reactants, bis(aminothiocarbonyl)disulfides were obtained via tandem nucleophilic addition/oxidative coupling reactions in moderate to excellent yields. In all the coupling reactions, the oxidant was air and CAN possibly acted as an SET catalyst.
The HgCl2-promoted guanylation reaction: The scope and limitations
作者:Catherine Levallet、Joanne Lerpiniere、Soo Y Ko
DOI:10.1016/s0040-4020(97)00193-2
日期:1997.4
The HgCl2-promoted guanylation reaction was studied with various substituted thiourea starting materials and the scope and limitations are presented. The process was found to be effective with thioureas containing at least one N-conjugated substituent. Such activating groups include N-carbonyl- (acyl, alkoxycarbonyl, carbamoyl, etc.), N-cyano-, N-sulfonyl-, and N-aryl- substituents.
Guanidine derivatives of the formula: ##STR1## in which R.sup.1 is a cyclohexyl, adamantyl, bicycloheptanyl, bicycloheptenyl, tricycloheptanyl or tetracyclononanyl radical and R.sup.2 is a phenyl or pyridyl radical optionally substituted by 1 or 2 halogen atoms, or alkyl, cyanoalkyl, alkoxycarbonyl or amino radicals, and the pharmaceutically-acceptable acid-addition salts thereof, active against rhinoviruses, are disclosed, along with processes for their manufacture, compositions containing them, a method of combatting rhinoviral infections and a method of selectively killing rhinoviruses in a mixed virus population.
AbstractA facile and efficient sonochemical method for the preparation of carbodiimides from their corresponding thioureas or ureas was described. Using Ph3P–I2 combination in the presence of triethylamine, various diaryl, aryl–alkyl, as well as dialkyl substituted substrates could be converted into carbodiimides in good-to-excellent yields within short reaction times under mild conditions with simple