Iridium di

Cl2lr2Cj2H5j, Iridium, di-p-chloro-bis[bis(cyclooctene)-, 28 91 Cl2LaLi02Si4C3oH g, Lanthanum, bisfri -... 

E. Kikuchi, Rhodium- and iridium-dis-persed porous alumina membranes and their hydrogen permeation properties, Catal. Today 2000, 56(1-3), 83-87. 

Q2lr2C32H3g, Iridium, di- -chloro-bis[bis(cyclooctene)-, 28 91 QgLaLiOjSigCgoHjg, Lanthanum, bis[tf -13-bis(trimethylsilyl)-cydopentadienyl]di-fi-diloro-bis(tetrabydraiuian)lithium-, 27 170 CljLagSigCggHgg, Lanthanum, tetrakis[it -13-lNs(trinmthylsilyI)cydopentadienyl]-di-fi-chloro-di-, 27 171 02LiNd02Si4C3gH, Neodymium,... 

Figure 6.24 The noj net in hexakis(i -cyano)-fais((T) -penUimelhyl-c> clapeiiladienyl)>(pyridine)-di-iridium-di-silver [31 ]. Iridium atoms are black and silver atoms grey.

Article previously published in the electronic Encyclopedia of Reagents for Organic Synthesis as Iridium, di-/x-chlorotetrakis[(l,2-tj)-cyclooctene]di-. DOI 10.1002/047084289X.rn01630. 

In the rhodium and iridium complexes, the C-coordination, carbene function, and cyclometallated cases prevail. Benzothiazole-2-thione was studied extensively as a ligand and various situations of the exocyclic S-monodentate coordination as well as N,S-combinations in the di-, tri-, and tetranuclear species were discovered. 

Finally, these aqueous suspensions of rhodium(O) and iridium(O) are the most efficient systems for the hydrogenation of a large variety of mono-, di-substituted and/or functionalized arene derivatives. Moreover, in our approach, the reaction mixture forms a typical two-phase system with an aqueous phase containing the nanoparticle catalyst able to be easily reused in a recycling process. 

The iridium complex composed of l/2[ Ir(OMe)(cod)2 ] and 4,4 -di-/ r/-butyl-2,2 -bipyridine (dtbpy) shows a high catalytic activity for aromatic G-H silylation of arenes by l,2-di-/z r/-butyl-l,l,2,2,-tetrafluorodisilane.142 The reaction of 1,2-dimethylbenzene with l,2-di-/< r/-butyl-l,l,2,2,-tetrafluorodisilane in the presence of l/2[ Ir(OMe)(cod)2 ] and dtbpy gives 4-silyl-l,2-dimethylbenzene in 99% yield (Equation (103)), which can be utilized for other functionalizations such as arylation and alkylation. 

The classical notion has been that iridium complexes can be effective hydrogenation catalysts, with defined limitations. In this respect, Crabtree and Morris made the key breakthroughs [9], and their catalyst (Fig. 31.16) has been widely employed for the reduction of simple alkenes. It was widely successful in the di-... 

The dichlororuthenium arene dimers are conveniently prepared by refluxing ethanolic ruthenium trichloride in the appropriate cyclohexadiene [19]. The di-chloro(pentamethylcyclopentadienyl) rhodium dimer is prepared by refluxing Dewar benzene and rhodium trichloride, whilst the dichloro(pentamethylcyclo-pentadienyl)iridium dimer is prepared by reaction of the cyclopentadiene with iridium trichloride [20]. Alternatively, the complexes can be purchased from most precious-metal suppliers. It should be noted that these ruthenium, rhodium and iridium arenes are all fine, dusty, solids and are potential respiratory sensitizers. Hence, the materials should be handled with great care, especially when weighing or charging operations are being carried out. Appropriate protective clothing and air extraction facilities should be used at all times. 

Ir4(CO)ii(PPh3)149 The structures of the di- and tri-substituted iridium derivative are shown in Fig. 14. In all cases, the phosphines are around the basal plane. However, whereas the two phosphines are in relative trans-positions in the di-substituted compound, in the tris-derivative two of the phosphines are obliged to occupy relative c/s-position and, as a result, are involved in more steric interaction. 

Reactions of amines with alkenes have been reviewed298,299. Alkali metal amides are active homogeneous catalysts for the amination of olefins. Thus diethylamine and ethylene yield triethylamine when heated at 70-90 °C at 6-10 atm in the presence of lithium diethylamide and /V./V./V. /V -tetrarncthylcthylcncdiaminc. Solutions of caesium amide promote the addition of ammonia to ethylene at 100 °C and 110 atm to give mixtures of mono-, di- and triethylamines300. The iridium(I)-catalysed addition of aniline to norbomene affords the anilinonorbomane 274301. Treatment of norbomene with aniline... 

One of the most active and well-studied catalytic borylation systems is that generated from iridium(l) precursors such as [lr(COD)Cl]2 or [lr(COD)(OMe)]2 and bipyridine type ligands such as 2,2 -bipyridine or 4,4 -di-ferf-butyl-2,2 -bipyridine (dtbpy). In 2002, Ishiyama, Miyaura, and Hartwig et al. reported that the combination of [lr(COD)Cl]2 and 2,2 -bipyridine catalyzes arene borylation in the presence of excess arene under mild conditions (80°C). When the catalyst is generated from [lr(COE)2Cl]2 and dtbpy, the reaction proceeds even at room temperature [78, 79]. The same groups optimized conditions and found that the combination of [Ir(COD) (OMe)]2 and dtbpy (10) is a highly effective catalyst in the borylation of arenes so that reactions can be successfully performed with equimolar ratio of arenes and... 

Protected primary allylic amines were generated from allylic carbonates and ammonia equivalents. Iridium-catalyzed allylic substitution has now been reported with sulfonamides [90, 91], imides [89, 91-93], and trifluoroacetamide [89] to form branched, protected, primary allylic amines (Table 5). When tested, yields and selectivities were highest from reactions catalyzed by complexes derived from L2. Reactions of potassium trifluoroacetamide and lithium di-tert-butyhminodi-carboxylate were conducted with catalysts derived from the simplified ligand L7. Reactions of nosylamide and trifluoroacetamide form singly-protected amine products. The other ammonia equivalents lead to the formation of doubly protected allylic amine products, but one protecting group can be removed selectively, except when the product is derived from phthalimide. 

Electron-rich iridium(l) complexes can perform C—H activation reactions under mild conditions [13]. In this line, acetone-dis solutions of the [(ri -l,3,5-C 5H3Me3)) lr(Ti -C2H4)(P Pr3)]BF4 complex, at room temperature, show deuterium incorporation to the ethane ligand, most likely due to the participation of hydrido vinyl iridium(lll) species, formed by the C—H activation of ethane, according to Scheme 2.25 [21]. 

The beneficial effects of chelating ligands were also demonstrated by Hartwig, Ishiyama and Miyaura [62]. This group isolated the iridium(I) complex [lr(Bpin)3(COE)(DTBPY) modified with simple 2,2 -bipyridine ligands (such as 4,4 -di-tert-butyl-2,2 -bipyridine DTBPY), which seemed to be responsible for the first catalytic C—H borylation at room temperature (Scheme 7.30). An extension... 

A convenient direct route has recently been described for obtaining regioregular polyalkylthiophenes using a tandem iridium-catalyzed borylation to produce the monomer, and a palladium-mediated coupling to produce the polymer [68]. The treatment of substituted thiophenes with B2pin2 in the presence of [lrCl2(COD)]2/ 4,4 -di-tert-butyl-2,2 -bipyridine (DTBPY) provided the expected monomer in 97% yield (Scheme 7.35). 

Iridium cationic complexes have recently been used as highly effective catalysts for the regioselective di- and tri-silylation of simple glycopyranosides with tert-butyldimethylsilane [76]. 

---