Presence Of Iridium Catalyst Research Articles

Ir(bis‐NHC)‐Catalyzed Direct Conversion of Amines to Alcohols in Aqueous Glycerol

Sustainable catalytic conversion of amines to alcohols was realized in the presence of iridium catalysts and aqueous glycerol. Iridium catalysts involving bis‐N‐heterocyclic carbene (bis‐NHC) show good reactivity and stability in the conversion of amines into alcohols in aqueous glycerol. The reaction was initiated with the dehydrogenation of amines and followed by hydrolysis and reduction. Iridium catalysts play dual roles in both the dehydrogenation and reduction steps. By employing glycerol as a solvent and hydrogen source, the final reduction was facilitated. The synthesis and characterization of various Ir(bis‐NHC) complexes are described along with the catalytic reaction results of the amine into alcohol conversion.

ChemInform Abstract: Recent Advances in Iridium‐Catalyzed Alkylation of C—H and N—H Bonds

AbstractReview: 76 refs.

Recent Advances in Iridium-Catalyzed Alkylation of C–H and N–H Bonds

Over the past few years, iridium complexes have been widely used in the direct functionalization of unactivated bonds. In the presence of iridium catalysts, inactive C–H and N–H bonds have been transformed into C–C and N–C bonds in dehydrative alkylation using alcohols, allylation using allyl carbonates, and alkylation using alkenes. Enantioselective variants of some reactions have also been reported.

Iridium-catalyzed asymmetric ring-opening of azabicyclic alkenes with alcohols

A novel asymmetric ring-opening reaction of N-substituted azabenzonorbornadienes with a wide variety of substituted benzyl alcohols and the addition reaction of N-substituted azabenzonorbornadienes with thiols are reported, affording the corresponding 1,2-trans-alkoxyamino products in moderate yields with excellent enantioselectivities (up to 94% ee) and the corresponding thiol addition products in high yields with lower enantiomeric excesses (ee) in the presence of iridium catalyst, respectively. The effects of ligands, catalyst loading, solvents and additives, and temperature were also investigated. The anti-configuration of the product 3c was confirmed by X-ray crystal structure analysis. A possible mechanism for the present catalytic reaction is proposed.

ChemInform Abstract: A Facile Synthesis of α‐Fluoro Ketones Catalyzed by [Cp*IrCl2]2.

AbstractThe direct fluorination of allylic alcohols is based on Selectfluor as fluorine source in the presence of iridium catalyst.

Monoalkylation of Acetonitrile by Primary Alcohols Catalyzed by Iridium Complexes

The monoalkylation of acetonitrile by primary alcohols was achieved in a one-pot sequence in the presence of iridium catalysts. A diversity of nitriles has been obtained from aryl- and alkyl-methanols in excellent yield.

ChemInform Abstract: Dehydrogenative Silylation of Terminal Alkynes by Iridium Catalyst.

Abstract Dehydrogenative silylation of terminal alkynes with hydrosilanes proceeds in the presence of iridium catalyst to afford the corresponding silylacetylenes. When phenylacetylene and triethylsilane were heated in dry DME in the presence of Ir4(CO)12–PPh3, (2-phenylethynyl)triethylsilane was obtained in 96% yield with little of hydrosilylated products. The present method is applicable for a variety of terminal alkynes and hydrosilanes to give the corresponding silylacetylenes in good yields with high selectivities.

Hydrogenation of β-N-Substituted and β-N,N-Disubstituted Enamino Esters in the Presence of Iridium(I) Catalyst

Several new β-amino esters were prepared in two simple steps from β-keto ester derivatives and primary and secondary amines under mild conditions. The hydrogenation of various enamino esters was performed at 50 ˚C in the presence of iridium catalysts. The new β-N-substituted amino esters were isolated in high yields.

Hydrogenation of Enol Phosphinates in the Presence of Iridium Catalysts with N,P-Ligands

Hydrogenation of Enol Phosphinates in the Presence of Iridium Catalysts with N,P-Ligands

Selective hydrogenation of carbonyl group of?,?-unsatueated aldehydes in the presence of iridium catalyst

α,β-Unsaturated aldehydes (furylacrolein, crotonaldehyde, cinnamaldehyde, citral) are quantitatively hydrogenated to the corresponding unsaturated alcohols in the presence of iridium catalyst. The hydrogenation of acrolein gives a mixture of products, containing mainly allyl alcohol.