Metal imides, cycloaddition reaction

Also, metal imides, such as the pinacolate complex of iridium 101, undergo a [2-F2] cycloaddition reaction with A,A -ditolylcarbodiimide to give the metallacycle 102. ... 

The cumulenes discussed in this book are subdivided into carbon- and noncarbon cumulenes, and the 1-carbon cumulenes (sulfines, sulfenes, thiocarbonyl S -imides and thiocar-bonyl S -sulfides) are excellent dipolar species. The 2-carbon or the center-carbon cumulenes (carbon dioxide and carbon sulfides) are less reactive but their imides (isocyanates, isothiocyantes and carbodiimides) readily participate in many of the discussed reactions. The 1,2-dicarbon cumulenes (ketenes, thioketenes and ketenimenes) similarly participate in cycloaddition reactions, as well as the more exotic 1,2-dicarbon cumulenes (1-silaalene, 1-phosphaallene and other metal allenes). In contrast, 1,3-dicarbon cumulenes are only... 

Also alkynylcarbene complexes can react as Michael acceptors with nucleophiles, forming 1,3-dien-l-ylcarbene complexes (Figure 2.17). Both carbon nucleophiles, such as, e.g., enamines [246-249], and non-carbon nucleophiles, such as imidates [250], amines [64,131,251], aliphatic alcohols [48,79,252], phenols [252], and thiols [252] can add to the C-C triple bond of alkynylcarbene complexes. Further reactions of the C-C triple bond of alkynylcarbene complexes include 1,3-dipolar [253,254], Diels-Alder [64,234,238,255-258] and [2 -i- 2] cycloadditions [259 -261], intramolecular Pauson-Khand reactions [43,262], and C-metallation of ethynylcarbene complexes [263]. 

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