PANEQUE SOSA , Margarita

In the mononuclear title iridium(III) complex, [Ir(C4H8)- (C15H22BN6)(C3H9P)], which is based on the [tris(3,5- dimethylpyrazol-1-yl)hydroborato]iridium moiety, Ir[TpMe2], the IrIII atom is coordinated by a chelating butane-1,4-diyl fragment and a trimethylphosphane ligand in a modestly distorted octahedral coordination environment formed...

In the title compound, [Ir(C15H22BN6)(C8H7O)Cl]·CHCl3, the Ir atom is formally trivalent and is coordinated in a slightly distorted octahedral geometry by three facial N atoms, one C atom, one O atom and one Cl atom. The Ir Ccarbene bond is strong and short and exerts a notable effect on the trans-Ir—N bond, which is about 0.10 A˚ longer than...

Members of a series of iridacyclopentenes of composition [TpMe2Ir(k2-C,C-CH2CR′=CRCH2)(CO)] (TpMe2=hydrotris(3,5-dimethylpyrazolyl)borate; R=R′=H, 1; R=Me, R′=H, 2; R=R′=Me, 3) have been subjected to common organic chemistry procedures for hydrogenation, cyclopropanation, epoxidation, water addition through hydroboration, cis-dihydroxylation,...

The Ir(III) pyridylidene TpMe2tiebar above startr(CH2CH2-o-tiebar above endC6H4)(tiebar above startCN(H)CHCHCHtiebar above endCH) (3; TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) reacts with oxygen (air), under mild conditions, to afford a bicyclic ether-semiaminal species. The new structure derives formally from two oxidative events. One is...

The dihapto coordination of two molecules of carbon dioxide to a square-planar MoP2(P-P) fragment (P=monodentate-, P-P=bidentate phosphi- ne ligands) can occur in several ways giving rise to different conformers. Compounds of this type have been prepared and their spectroscopic proper- ties investigated by variable temperature 'H and 31P NMR...

Thermal activation of terpyridine in the presence of an unsaturated Ir(III) fragment stabilized by a hydrotris(pyrazolyl) borate ligand gives rise to mononuclear complex 2 and binuclear 3, in which the polypyridine behaves, respectively, as a mono- or a bi-dentate N-heterocyclic carbene.

Catalytic dehydrogenation of ammonia-borane (NH3·BH 3, AB) and dimethylamine borane (NHMe2·BH 3, DMAB) by the PdII complex [(tBuPCP)Pd(H 2O)]PF6 [tBuPCP = 2,6-C6H 3(CH2PtBu2)2] leads to oligomerization and formation of spent fuels of general formula cyclo-[BH 2-NR2]n (n = 2,3; R = H, Me) as reaction byproducts, while one equivalent of H2 is...

We have synthesized a new type of metallaaromatic complexes, namely the hydride-β-iridanaphthalenes TpMe2tiebar above startr(H)[C(CH2R′)-C6H4-o-C(R)═tiebar above endC(R)] (benzo-3-H,CH2R′), by reaction of the benzo-iridacyclopentadiene TpMe2tiebar above startr[C6H4-o-C(R)═tiebar above endC(R)](OH2) (benzo-1-OH2) (TpMe2 =...

The reaction of the bis(ethylene) complex [TpMe2Ir(C2H4)2] (1) (TpMe: hydrotris(3,5-dimethylpyrazolyl)borate) with two equivalents of dimethyl acetylenedicarboxylate (DMAD) in CH2Cl2 at 25 °C gives the hydride–alkenyl species [TpMe2IrH{C(R)=C(R)C(R)=C(R)CH=CH2}] (2, R: CO2Me) in high yield. A careful study of this system has established the...

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...

The TpMe2Ir(III) complex 1-OH2 (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate), which contains a labile molecule of water and an iridium-bonded alkenyl moiety (−C(R)═C(R)–(R=CO2Me)) as part of a benzo-annulated five-membered iridacycle, reacts readily with the conjugated dienes butadiene and 2,3-dimethylbutadiene to afford the corresponding...

The fully CO2Me substituted aquo-iridacyclopentadiene 1 reacts with a variety of aromatic aldehydes, at 90–120 °C, with the formation of bicyclic Fischer-type carbenes, generated by the transfer of the aldehydic H atom to an α carbon of the metallacycle and concomitant bonding of the O atom to the adjacent β carbon. These carbenes have a...

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...

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.

The TpMe2-containing hydride-iridafurans 2a,b (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) cleanly reacted with ethylene to give the bicyclic derivatives 6a,b. Formation of the latter complexes is a reversible process, and it is proposed to occur by an electrocyclic ring closure that takes place between C2H4 and the 16e unsaturated...