HERNÁNDEZ JUÁREZ , Martín

The preparation of new Ru(ii) complexes incorporating fac-coordinated lutidine-derived CNC ligands is reported. These derivatives are selectively deprotonated by tBuOK at one of the methylene arms of the pincer, leading to catalytically active species in the hydrogenation of imines.

Coordination studies of new lutidine-derived hybrid NHC/phosphine ligands (CNP) to Pd and Ir have been performed. Treatment of the square-planar [Pd(CNP)Cl](AgCl2) complex 2a with KHMDS produces the selective deprotonation at the CH2P arm of the pincer to yield the pyridine-dearomatised complex 3a. A series of cationic [Ir(CNP)(cod)]+ complexes...

Iridium complexes based on deprotonated lutidine-derived CNP* pincers 2a/2b selectively catalyzed the hydroboration of CO2 under mild conditions (1–2 bar CO2, 30 °C) to methoxyborane using HBcat (TOF up to 56 h−1 ) and to the formate level with HBpin (TOF up to 1245 h−1 ). Interestingly, an intriguing, positive water effect on the reaction...

An iridium complex featuring a metalated lutidine-derived CNP ligand reacts with KOt Bu to yield a dimeric species with the two metal centers bound to the opposite ligands through the CHN arms. Furthermore, reaction with H2 in the presence of KOt Bu of the same iridium derivative results in the hydrogenation of the –CHQCH– imidazolylidene...

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 lutidine-derived CNP (C = N-heterocyclic carbene, NHC; P = phosphine) pincer ligands with two nonequivalent Brønsted acid/base sites have...

The iridium complex 1 based on a metalated CNP ligand containing an imidazolin-2-ylidene fragment has been prepared by treatment of the ligand precursor 4 with Ag2O followed by reaction with [IrCl(COE)2]2. The chlorohydride imidazolidin-2-ylidene complex 6, which is isostructural to 1, was synthetized by reaction of the previously reported...

Ru complexes based on lutidine-derived pincer CNN(H) ligands having secondary amine side donors are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Reaction of a Ru-CNN(H) complex with an excess of base produces the formation of a Ru(0) derivative, which is observed under catalytic conditions.

A series of Ru complexes containing lutidine‐derived pincer CNC ligands have been prepared by transmetalation with the corresponding silver‐carbene derivatives. Characterization of these derivatives shows both mer and fac coordination of the CNC ligands depending on the wingtips of the N‐heterocyclic carbene fragments. In the presence of tBuOK,...