Isothiocyanate chemistry

Zhang Y and Talalay P. 1994. Anticarinogenic activities of organic isothiocyanate chemistry and mechanisms. Cancer Res 54 1976s-1981s. 

Zhang, Y. and Talalay, P. (1994) Anticarcinogenic activities of organic isothiocyanates chemistry and mechanisms. Cancer Res., 54,19765-81S. 

Zhang Y, Talalay P (1994) Anticarcinogenic aetivi-ties of oiganie isothiocyanates chemistry and meeh-anisms. CaneerRes 54 1976-1981... 

A major advance was devised by Pehr Edrnan (University of Lund, Sweden) that has become the standard method for N-terminal residue analysis. The Edman degradation is based on the chemistry shown in Figure 27.12. A peptide reacts with phenyl isothiocyanate to give a phenylthiocarbamoyl (PTC) derivative, as shown in the first step. This PTC derivative is then treated with an acid in an anhydrous medium (Edrnan used nitrornethane saturated with hydrogen chloride) to cleave the amide bond between the N-terminal anino acid and the remainder of the peptide. No other peptide bonds are cleaved in this step as amide bond hydrolysis requires water. When the PTC derivative is treated with acid in an anhydrous medium, the sulfur atom of the C=S unit acts as... 

Flamers R. J., Coulter S. K., Ellison M. D., Flovis J. S., Padowitz D. F., Schwartz M. P., Greenlief C. M., Russell J. N. Jr Cycloaddition Chemistry of Organic Molecules With Semiconductor Surfaces Acc. Chem. Res. 2000 33 617 624 Keywords carbonyi group, semiconductor materiais, surface reaction, aikenes, aromatic compounds, azo compounds, cycioaikadienes, isothiocyanates, unsaturated compounds... 

In analogous fashion to isocyanate chemistry, isothiocyanates like 125 can be utilized to produce the corresponding quinazoline-2-thioxo-4-ones. Makino and co-workers reported the solid phase synthesis of quinazoline derivatives 126 through the reaction of polymer-bound primary amines 124 with isothiocyanates 125 <00TL8333>. 

In carbohydrate chemistry, the most described method for the preparation of saccharidic thionocarbamates involves preliminary introduction of the amine function on a partially or non-protected saccharidic template. The condensation of amino sugars with carbon disulfide or thiophosgene leads to cyclization in 1,3-oxazolidine- or l,3-oxazine-2-thiones. This reaction involves the formation of an intermediate isothiocyanate, which reacts further with a 3- or y-located hydroxyl group. The viability and facility of this process depends on the saccharidic ring size and the inherent strain. Some major rules can be put into light from the cases studied 30... 

Figure 4.10 Selected ion-monitoring chromatograms of the thiocyanate and isothiocyanate derivatives of methyl, ethyl and isopropyl mesylates (final concentrations 0.25 pg/ml). Reproduced from [60] by permission of the Royal Society of Chemistry.

Combinatorial methods have been employed to convert the very simple thiophene precursor 446a into a variety of N-substituted products 447. The process first involves conversion of the amino group into the isothiocyanate followed by treatment with substituted hydrazides (Equation 168) <2004JC0573>. Other derivatives have been prepared using similar chemistry. 

For reviews of the preparation and reactions of isocyanates and isothiocyanates, see. respectively, the articles by Richter Ulrich, pp. 619-818, and Drobnica Kristian Augustin pp. 1003-1221, in Patai The Chemistry of Cyanates and Their Thio Derivatives, pt. 2 Wiley New York, 1977. 

The Chemistry of Acyl and Sulphonyl Isocyanates, Isothiocyanates, and Isoselenocyanates ... 

The Chemistry of Ethoxycarbonyl Isothiocyanate and Related Compounds R. Esmail and F. Kurzer, Synthesis, 1975, 301-314. 

In sharp contrast to the thioketenes, carbon disulfide S=C=S, carbon oxysulfide 0=C=S and the isothiocyanates R-N=C=S are stable compounds although highly reactive, and are widely used in organosulfur chemistry. Some of their reactions with organometallics have been mentioned previously (see Section 2.8.3). 

MONOSACCHARIDE ISOTHIOCYANATES AND THIOCYANATES SYNTHESIS, CHEMISTRY, AND PREPARATIVE APPLICATIONS... 

In an article that collates information not extensively treated before, Z. J. Witczak (West Lafayette) describes the synthesis, chemistry, and preparative applications of monosaccharide thiocyanates and isothiocyanates the thiocyanate anion is an ambident nucleophile of great synthetic versatility in approaches to nucleoside analogs and to thio and deoxy sugars. 

The Edman degradation method for polypeptide sequence determination. The sequence is determined one amino acid at a time, starting from the amino-terminal end of the polypeptide. First the polypeptide is reacted with phenylisothiocyanate to form a polypeptidyl phenylthiocarbamyl derivative. Gentle hydrolysis releases the amino-terminal amino acid as a phenylthiohydantoin (PTH), which can be separated and detected spectrophoto-metrically. The remaining intact polypeptide, shortened by one amino acid, is then ready for further cycles of this procedure. A more sensitive reagent, dimethylaminoazobenzene isothiocyanate, can be used in place of phenylisothiocyanate. The chemistry is the same. 

In recent years remarkable progress has been made in the chemistry of organosilicon compounds containing a double bond to group 14 and group 15 elements. The reaction of a silylene-isocyanide complex with nitrile oxide generated the intermediate silanone, which with phenyl isothiocyanate afforded 1,3,2-oxathiasiletane 63, which is sensitive to hydrolysis (Equation 10) <2000CL244>. 

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