A new and efficient method based on the simple metalating reagent Fe(CO)5 has been developed for the straightforward synthesis of well defined cyclometalled PCP iron carbonyl pincer complexes. The reaction proceeds cleanly under mild conditions at 30 °C and UV irradiation. Four hydride pincer complexes are synthesized and fully characterized as well as an intermediate dinuclear species. The new iron complexes are active and selective catalytic precursors for the dehydrogenative borylation of styrene with HBpin.

A family of iron Knölker-type complexes bearing an N-heterocyclic carbene (NHC) ligand has been synthesized from the corresponding tricarbonyl­(η4-cyclopentadienone)iron complex by reaction with the in situ generated NHC ligand, under UV irradiation (350 nm) at room temperature. The six complexes, obtained in good yields (64–84%) after purification on column chromatography, were fully characterized, including X-ray diffraction and electrochemical studies. The activity of these complexes in catalysis has been demonstrated for the dehydration of primary benzamides into benzonitriles under hydrosilylation conditions using inexpensive polymethylhydrosiloxane (PMHS) as the hydrosilane at 100 °C.

No abstract

Reaction of N-heterocyclic carbene iron(0) tetracarbonyl complexes with hydrosilanes (triphenylsilane, methyldiphenylsilane and diphenylsilane) under UV irradiation (350 nm) afforded the octahedral N-heterocyclic carbene iron (II) silyl hydride complexes in yields up to 95 %, resulting from the oxidative addition of the hydrosilane. Eight iron silyl hydrides were obtained and characterized by NMR and X-ray diffraction analysis. Noticeably, the geometry of the ironhydride complexes and the bent structures of the carbonyl ligands were rationalized by DFT calculations.

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The combination of various reactions in one operational step leads to many advantages in synthetic strategies, such as a lower consumption of resources, effort, and time, when intermittent workup and purification steps can be avoided. The hydroformylation reaction of acrylates gives access to 2-formylpropanoates, which thanks to their structural features constitute useful intermediates in the synthesis of more complex compounds. Herein, we report a simple and convenient one-pot strategy to synthesize functionalized carbonyl compounds starting from these readily available substrates, via tandem or one-pot hydroformylation, Michael addition, and aldol reactions.