Thiocarbonates aminolysis

Aminolysis of a series of aryl 2,4-dinitrophenyl carbonates by a series of quinuclidines gave linear Br0nsted-type plots, the magnitudes of their slopes confirming their mechanisms as concerted.40 A comparison41 of the aminolysis, by primary amines, of 4-nitrophenyl phenyl carbonate (31 X = O) with its thiono analogue (31 X = S) is discussed in the section Thioacids, Thioesters, Thiolactones, and Thiocarbonates below. 

The aminolysis of the aryl 5-methyl thiocarbonates (62-64) by secondary alicyclic amines in aqueous solution at 25 °C proceeded by a stepwise mechanism in the case of the 4-nitro compound (62), but by a concerted mechanism for the other two substrates (63, 64).52... 

The kinetics of the reaction of hydroxyl groups of monosaccharides and polyols with benzyl isothiocyanate has been checked by Augustin and Balaz using UV spectroscopy.289 However, because of the reversibility of the reaction, this procedure is not. of synthetic utility. O-Sugar thiocarbamates have been more conveniently prepared by aminolysis of thiocarbonate derivatives290,291 or by thiocarbamoylation of free hydroxy] groups with 1,1 -tbiocarbonyldiimidazoie.7 286 288... 

Thioureas have also been synthesized by aminolysis of other thiocarbonic acid derivatives. Carbon disulphide reacted with guanidines to yield RNHC(S)NH2 along with 1,3,5-thiadiazines (14). The tricyclic compound (15) was formed by... 

The aminolysis of 0-methyl S -(Z-aryl) thiocarbonates (45) by X-benzylamines in MeCN at 318 K (Scheme 15) to the corresponding carbamates (46) proceeded by a concerted mechanism. The kinetic isotope effects involving deuterated benzylamines XQH4CH2ND2 were large, h/ jj = 1.3-1.75, suggesting that the N-H(D) bond is partially broken in the TS by forming a four-centre cyclic structure (47). ... 

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