Formation via cross-coupling

Aryl/Alkenyl Ether Formation via Cross-Coupling Reactions 650... 

Equation 12 indicates that NEP formation via cross-coupling reactions, NEP c, correlates with the logarithm of ( ]o. 

Li, G.Y., Zheng, G. and Noonan, A.R (2001) Highly active, air-stable versatile paUadium catalysts for the C-C, C-N, and C-S bond formations via cross-coupling reactions of aryl chlorides. J. Org. Chem., 66, 8677-81. 

There are other examples of carbonylation of terminal alkynes, which involve the in-termolecular reaction of an acylpalladium complex with an alkyne moiety, but they most probably also involve carbon-carbon bond formations via cross-coupling rather than acylpalladation (Scheme 21). 

Beletskaya IP, Ananikov VP. Transition-metal-catalyzed C S, C Se, and C Te bond formation via cross-coupling and atom-economic addition reactions. Chem. Rev. 2011 111 1596-1636. 

Carbon—Carbon Bond formation via Cross-Dehydrogenative Coupling 168... 

Carbon—Carbon Bond Formation via Cross-Dehydrogenative Coupling... 

Because iron is a cheap, abundant, non-toxic, and environmentally benign metal, it has attracted a lot of attention in catalysis over the last few years. In particular, iron-based catalytic systems showed great promise for the formation of carbon-carbon bonds via cross-coupling reactions. In most cases, however, simple inorganic salts or coordination compounds of Fe and Fe are employed as catalyst precursors. Recourse to NFIC ligands to fine-tune the catalytic properties of iron active centres is still scarce in organic synthesis and was documented for only a handful of reactions. Other important transformations mediated by NHC Fe species were found in the related fields of biocatalysis and organometallic synthesis, and will be discussed first. 

To date, catalytic applications of NHC-Fe systems are still scarce and do not reflect the full potential of this cheap, abundant and non-toxic metal that shows great promise for the formation of carbon-carbon bonds via cross-coupling reactions. Recourse to ill-defined species generated in situ and difficulties in understanding the intimate nature of reaction mechanisms do not ease the development of organo iron catalysis. Support from the related field of iron biocatalysis and recent discoveries in organometallic chemistry are expected to provide help and inspiration for further advances. 

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