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The formation of carbon–heteroatom bonds (C–X bonds with X=N, S, P) upon addition of X-nucleophiles or X-electrophiles to unsaturated alkynes and alkenes, cross-coupling reactions, cycloadditions, tandem or consecutive reactions, or C–H functionalization is an attractive strategy in organic synthesis and is an intensive research area. Many organometallic species, more specifically palladium, nickel, and rhodium complexes, have paved the way to useful synthetic applications in this field. This chapter will cover iron-catalyzed bond-forming reactions between carbon and a heteroatom.

The newly developed title complex proves efficient in the reductive amination of various aldehydes and ketones with primary aliphatic and aromatic amines as well as secondary amines.

This review presents recent advances in reduction of carboxylic and carbonic derivatives by means of iron catalysis. It reveals the strong efforts, which have been devoted to the discovery of new ligands and catalysts during the last decade.

Reductive amination under hydrogen pressure is a valuable process in organic chemistry to access amine derivatives from aldehydes or ketones. Knclkers complex has been shown to be an efficient iron catalyst in this reac- tion. To determine the influence of the substituent on the cyclopentadienone ancillary ligand, a series of modified Knclkers complexes was synthesised and fully characterised. These com- plexes were also transformed into their analogous acetonitrile iron-dicarbonyl complexes. Catalytic activities of these complexes were evaluated and com- pared in a model reaction. The scope of this reaction is also reported. For mechanistic insights, deuterium-label- ling experiments and DFT calculations were undertaken and are also present- ed.

5 Iron(II) complexes are tested as catalysts for the isomerization of trifluoromethylated allylic alcohols.

Since the discovery of the first air stable NHC, this class of compounds has been intensively studied and applied in organometallic chemistry and homogeneous catalysis due to the stability brought to the metal centre. Alternatively, phosphorus based family ligands have already a very long history in these fields of chemistry. It was naturally obvious that the NHC and the phosphorus ligands had to be mixed for the best of organometallic chemistry and homogeneous catalysis. This perspective will highlight the new synthetic routes for NHC bearing a phosphorus moiety such as NHC-phosphenium salt, N-phosphorylated-imidazolium salt, 4-phosphino or 4,5-diphosphino-imidazolium salt and tethered phosphino-imidazolium salt. Then, the recent applications in organometallic chemistry and homogeneous catalysis will be presented.

The first homogeneous well-defined iron catalyst for the title reaction under low pressure of hydrogen is reported.

Furans and pyrroles were prepared via the gold(I)-catalyzed alkyne hydration of diynes. The use of [Au(IPr)OH] as precatalyst in a silver-free protocol permits low catalyst loadings and in situ generation of the active cationic gold species. A detailed computational study confirmed the experimental results and supports the proposed mechanism.

Gold-catalyzed cyclization of propargylic acetates (I) provides access towards acetoxyindenes (II) in high yields.

The use of [(IPr)AuOH] permits the generation of Au(I)-amine complexes by a Ag-free protocol.

The use of [(IPr)AuOH] as versatile, air- and moisture-stable pre-catalyst permits the in situ generation of the cationic gold(I) species [(IPr)Au]X after reaction with a Bronsted acid. This catalytic system presents as a main advantage the lack of use of a silver salt activator or co-catalyst which is often air-, light- and moisture-sensitive. A general gold(I)-catalyzed procedure using this in situ activation at very low catalyst loading is reported for the hydration of a broad range of internal and terminal alkynes.

A convenient route for the synthesis of a variety of amino-bispyridyl compounds is introduced. Bispyridylamines were prepared in three steps from commercially available 2,6-dibromopyridine, via a copper mediated alkylation followed by two consecutive N-arylation reactions catalyzed by copper and palladium, respectively.

2-(Pent-4-ynyl)norbornadienes undergo an intramolecular [2 + 2 + 2] cycloaddition in the presence of (nbd)RuCl2(PPh3)2 as a catalyst affording annelated deltacyclenes in good to excellent yields. The usefulness of the reaction is illustrated by the straighforward conversion of pentacyclene 2a into the angularly fused triquinane 19.