Kaur, Mandeep; U Din Reshi, Noor; Patra, Kamaless; Bhattacherya, Arindom; Kunnikuruvan, Sooraj; Bera, Jitendra K. published the artcile< A Proton-Responsive Pyridyl(benzamide)-Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols>, Electric Literature of 5344-90-1, the main research area is pyridylbenzamidecarbene iridium complex preparation catalyst alkylation ketone alc; crystal structure pyridylbenzamidecarbene iridium complex; mol structure pyridylbenzamidecarbene iridium complex; Borrowing-Hydrogen; Homogeneous Catalysis; Hydrogen transfer; Metal-Ligand Cooperation; Proton-Responsive Ligand; Reaction Mechanism.
A Cp*Ir(III) complex (1) of a newly designed ligand L1 featuring a proton-responsive pyridyl(benzamide) appended on N-heterocyclic carbene (NHC) was synthesized. The mol. structure of 1 reveals a dearomatized form of the ligand. The protonation of 1 with HBF4 in THF gives the corresponding aromatized complex [Cp*Ir(L1H)Cl]BF4 (2). Both compounds were characterized spectroscopically and by x-ray crystallog. The protonation of 1 with acid was examined by 1H NMR and UV-visible spectra. The proton-responsive character of 1 is exploited for catalyzing α-alkylation of ketones and β-alkylation of secondary alcs. using primary alcs. as alkylating agents through H-borrowing methodol. Compound 1 is an effective catalyst for these reactions and exhibits a superior activity in comparison to a structurally similar Ir complex [Cp*Ir(L2)Cl]PF6 (3) lacking a proton-responsive pendant amide moiety. The catalytic alkylation was characterized by a wide substrate scope, low catalyst and base loadings, and a short reaction time. The catalytic efficacy of 1 is also demonstrated for the syntheses of quinoline and lactone derivatives via acceptorless dehydrogenation, and selective alkylation of two steroids, pregnenolone and testosterone. Detailed mechanistic studies and DFT calculations substantiate the role of the proton-responsive ligand in the H-borrowing process.
Chemistry – A European Journal published new progress about Alkylating agents (pyridyl(benzamide) Ir complexes). 5344-90-1 belongs to class alcohols-buliding-blocks, and the molecular formula is C7H9NO, Electric Literature of 5344-90-1.
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts