@article {48311, title = {Iron-catalyzed magnesium-mediated formal hydroformylation of alkynes and alkenes}, journal = {ChemCatChem}, volume = {15}, year = {2023}, month = {FEB }, type = {Article}, abstract = {

Alkynes and alkenes are routinely converted to corresponding synthetically versatile aldehydes using rhodium-catalyzed hydroformylation. However, rhodium is rare, precious, costly, and depleting at a considerably high rate. Reported here is iron-catalyzed, magnesium-mediated, formal hydroformylation of alkynes and alkenes in the absence of syngas. Readily available FeCl2 in the presence of alkyl magnesium halide, and dimethyl formamide, catalyzes hydroformylation of various alkynes and selectively produces alpha,beta-unsaturated aldehydes in good to excellent conversion. Mechanistic investigations revealed the presence of vinyl magnesium intermediate, the kinetic study disclosed the first-order dependence of the reaction on iron loading, and the control experiment authenticated the iron catalyst{\textquoteright}s homogeneous nature. The scope of this methodology was amplified, and 20 alkenes were examined. [Fe(acac)(3)] in the presence of ligand, alkyl magnesium halide, and dimethyl formamide catalyzed the hydroformylation of alkenes and displayed good to excellent conversion. An earth-abundant iron catalyst offering a syngas cylinder-free safe alternative to high-pressure hydroformylation has been reported.

}, keywords = {aldehydes, alkenes, Alkynes, Hydroformylation, iron catalysis}, issn = {1867-3880}, doi = {10.1002/cctc.202201394}, author = {Tewari, Tanuja and Kumar, Rohit and Chikkali, Samir H.} } @article {49331, title = {Iron in organometallic transformations: a sustainable substitute for noble metals}, journal = {ChemCatChem}, volume = {16}, year = {2024}, month = {OCT }, type = {Review}, abstract = {

Transition metal catalysis plays a pivotal role in chemical synthesis. Noble metals often grab significant attention in organometallic catalysis due to their high reactivity. However, the serious issues associated with these metals such as low abundance, toxicity, geopolitical limitations, and volatile prices are driving the scientific community to discover sustainable alternatives. In this context, iron appears to be the first choice as an alternative metal due to its unique properties, including a range of stable oxidation states, Lewis acidity, high abundance in the earth{\textquoteright}s crust, and low toxicity. Over the past two decades, substantial progress has been made in iron catalysis. This overview examines the recent developments in iron-catalyzed industrially relevant transformations such as hydroformylation, olefin isomerization, hydrosilylation, hydrophosphination, carbonylation, Wacker-type oxidation, and plastic depolymerization. As witnessed throughout this review, the performance of iron can be significantly altered by suitable ligand selection and by tailoring the electronic and steric properties of the iron center. While noble metals remain the industry work-horse, iron is inching closer and with extensive scientific understanding, it may replace noble metals in the near future. Late transition metals catalyze several reactions and have been the industry work-horse for decades. While, earth abundant metals are rarely used in industrially relevant transformations. In this overview, we examine the recent development in iron-catalyzed industrially relevant reactions such as hydroformylation, olefin isomerization, hydrosilylation, hydrophosphination, carbonylation, Wacker-type oxidation, and plastic depolymerization. Iron is inching closer and may replace noble metals in near future. image

}, keywords = {Alkene Isomerization, alkyne, Carbonylation, depolymerization, Hydrophosphination, Hydrosilylation, iron catalysis}, issn = {1867-3880}, doi = {10.1002/cctc.202400756}, author = {Kumar, Rohit and Tewari, Tanuja and Chikkali, Samir H.} } @article {49597, title = {Iron-catalyzed chemoselective reduction of enimines to N-Allylic amines via hydrosilylation}, journal = {Asian Journal of Organic Chemistry}, volume = {14}, year = {2025}, month = {MAY}, type = {Article}, abstract = {

Chemoselective hydrosilylation of unsaturated imines is challenging as the two double bonds compete for the reaction. Here in, we report an iron-catalyzed chemoselective hydrosilylation of enimines leading to the generation of allyl amines in the presence of phosphine ligand. A low-valent Fe(0) complex [(BDA)Fe(CO)3] catalyzed the hydrosilylation of enimine at room temperature and exhibited broad substrate scope including a variety of enimine (cinnamylimine, allylimine) and ketimine. Mechanistic investigations revealed that the reaction proceeds through an oxidative addition of the silane compound, leading to the formation of an iron hydride intermediate. Subsequently, a two-electron pathway facilitates the hydrosilylation of the enimine substrate. This has been supported by preparing a well-defined Fe(II)-silane complex and using it as a catalyst control. Based on experimental and computational investigations, a plausible Chalk-Harrod-type mechanism is proposed.

}, keywords = {Cinnamyl amine, Imine hydrosilylation, iron catalysis, Iron hydride, Phosphine}, issn = {2193-5807}, doi = {10.1002/ajoc.202400762}, author = {Tewari, Tanuja and Shaikh, Maulali H. and Sharma, Himanshu and Vanka, Kumar and Chikkali, Samir H.} }