isothiocyanaten

Isothiocyanates are a class of organic compounds that contain the isothiocyanate functional group, N=C=S, typically written as R–N=C=S where R represents an alkyl, aryl, or other substituent. They are organosulfur compounds that are widely used in synthesis and occur naturally in some plants. The isothiocyanate group is highly electrophilic at the central carbon and reacts readily with nucleophiles such as amines, thiols, and other soft nucleophiles, enabling the formation of thioureas, dithiocarbamates, and related derivatives.

In laboratory synthesis, isothiocyanates are commonly prepared by converting primary amines to the corresponding isothiocyanates using thiophosgene (CSCl2) or related phosgene substitutes, often with base to scavenge generated hydrogen chloride. Other routes include oxidative methods from thioureas or multistep approaches starting from amines. The resulting RN=C=S compounds vary in volatility, color, and reactivity depending on the R group.

Natural occurrence is notable for certain isothiocyanates produced by plants, particularly glucosinolate hydrolysis in crucifers. Allyl isothiocyanate (AITC), phenethyl isothiocyanate (PEITC), and benzyl isothiocyanate (BITC) are among well-studied examples that contribute to the characteristic pungent aromas and are investigated for biological activities.

Applications of isothiocyanates span organic synthesis as versatile building blocks and as precursors to more complex sulfur-containing compounds. They have been studied for antimicrobial and anticancer properties, though the latter remains an area of active research. Safety considerations are important, as many isothiocyanates are irritants and can be hazardous upon exposure.