Selective, Base-Free Hydrogenation of Aldehydes Catalyzed by Ir Complexes Based on Proton-Responsive Lutidine-Derived CNP Ligands was written by Sanchez, Praxedes;Hernandez-Juarez, Martin;Rendon, Nuria;Lopez-Serrano, Joaquin;Alvarez, Eleuterio;Paneque, Margarita;Suarez, Andres. And the article was included in Organometallics in 2021.Formula: C10H22O The following contents are mentioned in the article:
Metal catalysts based on ligands containing proton-responsive sites have found widespread applications in the hydrogenation of polar unsaturated substrates. In this contribution, Ir complexes incorporating 2-phosphinomethyl-6-imidazolylmethylpyridine, lutidine-derived CNP pincer ligands (C = N-heterocyclic carbene, NHC; P = phosphine) with two nonequivalent Bronsted acid/base sites have been examined in the hydrogenation of aldehydes. To this end, Ir(CNP)H2Cl complexes were synthesized in two steps from the CNP ligand precursors and Ir(acac)(COD). These derivatives react with an excess of NaH to yield the trihydride derivatives Ir(CNP)H3, which were assessed as catalyst precursors in the hydrogenation of a series of aldehydes. The catalytic reactions were performed using com.-grade substrates under neutral, mild conditions (0.1 mol % Ir-CNP; 4 bar H2, room temperature) with high conversions and selectivities for the reduction of the carbonyl function in the presence of other readily reducible groups such as C:C, nitro, and halogens. Reaction of an Ir(CNP)H2Cl complex with base in the presence of an aromatic aldehyde produces the reversible formation of alkoxide Ir complexes in which the aldehyde is bound to the deprotonated pincer framework (CNP*) through the CH-NHC arm of the ligand. These species, along with a carboxylate complex resulting from the Ir mediated oxidation of the aldehyde by water, is observed in the reaction of Ir(CNP)H3 with benzaldehyde. Finally, investigation of the mechanism of the hydrogenation of aldehydes has been carried out by means of DFT calculations considering the involvement of each arm of the Ir-CNP/CNP* derivatives Calculations support a mechanism in which the catalyst switches its metal-ligand cooperation sites to follow the lowest energy pathway for each step of the catalytic cycle. This study involved multiple reactions and reactants, such as 3,7-Dimethyloctan-1-ol (cas: 106-21-8Formula: C10H22O).
3,7-Dimethyloctan-1-ol (cas: 106-21-8) belongs to alcohols. Under appropriate conditions, inorganic acids also react with alcohols to form esters. To form these esters, a wide variety of specialized reagents and conditions can be used. Tertiary alcohols cannot be oxidized at all without breaking carbon-carbon bonds, whereas primary alcohols can be oxidized to aldehydes or further oxidized to carboxylic acids.Formula: C10H22O
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