Iridium complexes containing

Scheme 8.18 Hydrogenations of olefins with iridium complexes containing dithio-ether ligands with a pyrrolidine backbone.

Scheme 8.22 Hydrogenation of acetamidoacrylic acid with iridium complexes containing dithioether ligands.

In situ-generated iridium complexes containing bulky 3,3 -substituted H8-phosphoroamidites 20 as ligands catalyzed the asymmetric hydrogenation of... 

An unusual peroxo-bridged binuclear iridium complex containing an Ir—Ir bond has been reported (135a, 135b). The reaction of the electron-... 

Rasmussen, S.C., Richter, M.M., Yi, E., Place, H. and Brewer, KJ. (1990) Synthesis and characterization of a series of novel rhodium and iridium complexes containing polypyridyl bridging ligands Potential uses in the development of multimetal catalysts for carbon dioxide reduction. Inorg. Chem., 29, 3926—3932. 

Fig. 13 Iridium complexes containing a chiral phosphine-carbene ligand...

The reaction of 3,4-dihydroisoquinoline A-oxide (74) and methacrylonitrile in the presence of cationic half-sandwich rhodium and iridium complexes containing a chiral diphosphine ligand was analyzed. The cycloadditions occurred with excellent regio- and diastereoselectivity and low-to-moderate enantioselectivity. Analysis of the catalytic system showed the formation of two epimeric complexes 75 containing the dipolarophile methacrylonitrile. The reaction of one of the isolated diastereopure complexes 75 with 74 afforded cycloadduct 76 with high enantioselectivity. A recycling procedure was developed in order to increase the adduct/catalyst ratio <07CEJ9746>. 

Iridium complexes containing 1,2- and l,7-dicarba-closo-dodecarborane(12) (carb) are formed through a metal-carbon cr bond ... 

The iridium complex contained a tightly bound carbonyl group, unlike the rhodium complex, in accord with the stronger bonding of CO groups to 5d than to transition metals (216). Related iron and ruthenium carbonyl porphyrins have also been described 14, 217, 461). 

Hydrogen addition to Ir(CO)(dppe)(X) leads first to the isomer with X trans to one phosphorus of dppe in a reversible reaction. This kinetic isomer then rearranges to the thermodynamic isomer that has CO trans to a phosphorus atom of dppe. For X = H or PPh3, no rearrangement of the initially formed product is observed . Addition of H2 to an iridium complex containing the optieally active diphosphine chiraphos [bis(S),(S)-2,3-(diphenylphosphino)butane] was described - . The H2 addition to analogues of... 

Five- and six-coordinate rhodium and iridium complexes containing... 

Iridium complexes containing triphenylphosphine, e.g., HIr(CO)2(PPh3)2, in propionic acid catalyze ethylene carbonylation to propionic anhydride . Reaction occurs at a reasonable rate at 195°C and 5 Pa of CO/ethylene pressure. The corresponding Rh complexes are ineffective. The reaction is inoperative with higher olefins, even propylene. 

The synthesized zwitterionic iridium complexes containing various chiral P, N ligands with imidazoline or oxazoline were used as precatalysts for the asymmetric hydrogenation of unfunctionalized olefins. The cationic complexes with fluorinated borates as anions were superior catalysts in dichloromethane, whereas the iridium betaines were good catalysts in pure hydrocarbons. ... 

A series of benzylidene and low-valent alkylidene complexes have also been prepared from sulfur ylides. Deprotonation of benzyl or alkyl diphenylsulfonium salts with a strong base, such as KN(SiMe3)2, KNPr j or LiNPr generates the corresponding sulfur ylide. Reaction of this ylide with low-valent ruthenium, osmium, rhodium, or iridium complexes containing a labile ligand leads to transfer of the carbene unit from sulfur to... 

Many diastereoselective allylations form a new stereocenter at one of the allylic carbons and at the nucleophilic carbon. For example, an iridium complex containing a phosphite ligand catalyzes enantioselective and diastereoselective formation of products containing two stereocenters, one at the original nucleophile and one at the original allyl electrophile (Equation 20.58). In another example shown in Equation 20.59, Trost s palladium catalyst leads to the reaction of allylic esters with chiral azlactone pronucleophiles with high diastereomeric and enantiomeric excess, as does the related molybdenum catalyst. In these cases, the metal appears to control the new stereocenter at the allyl group, as well as the relationship between this stereocenter and the new stereocenter formed at the nucleophile. 

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