PKR reaction

The PKR reaction has always been characterized by good functional group compatibility. Examples abound where amines, amides, sulfonamides, sulfides, alcohols, ketones, esters, and silyl ethers are contained in the reactants. In addition, because substituted alkenes react more slowly than unsubstitued alkenes selectivity can be achieved when multiple alkenes are contained in the reactants. An interesting example of functional group compatibility was demonstrated in which a metal carbene not only survived the PKR but accelerated it. For example, the tungsten carbene 19 formed the cyclopentenone 20 in 80% yield at 0 °C. 

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