Hydrido-halide

The reaction starts with the oxidative addition of an aryl halide (Cl, Br or I) to palladium zero. The next step is the insertion of an alkene into the palladium carbon bond just formed. The third step is (3-hydride elimination giving the organic product and a palladium hydrido halide. The latter reductively eliminates HX, which reacts with base to give a salt (Figure 13.15). 

Several effects are related to the nature of the silicon halide. Hydrido halides usually react readily with a range of anions, while organosilicon halides may not for instance, HgSiCU reacts with Co(CO)J in ether giving good yields of silicon-cobalt derivatives (2), while MesSiCl does not (336). This is probably related in the main to the electron-accepting... 

Complexes with chelating polysulfidc ligands can be made either by reacting complex metal halides with. solutions of polysulfides or by reacting hydrido complexes with elemental... 

These reactions give products similar to those described in 8.3.2.1. Transition-mclal hydrido complexes react with a halogen derivative of a group-IB metal to form a hydrogen halide and the required metal-metal bond ... 

B,) Treatment of an organo- or a hydrido-nickel(II) compound with a Lewis acid. Organometallic compounds, such as alkylaluminum halides, which have Lewis acid properties, can also be used. 

When nickel(II) salts containing a coordinating anion (halide and pseudohalide) are reacted with NaBH4 in the presence of np3, trigonal bipyramidal nickel(I) complexes of the type [NiXnp3], in which the coordinating anion occupies die axial position, 39,340 are obtained. When nickel(II) salts with poorly coordinating anions are used, non-stoichiometric hydrido complexes of nickel(II) are obtained (equations 108 and 109). 

Palladium(O) complexes undergo oxidative addition to form Pd11 dH complexes readily. They form hydrido, chloro or dichloro species with HC114,24,35 and also react with alkyl and aryl halides.36 52 These reactions are exemplified in Scheme 3. 

The products of oxidative addition of acyl chlorides and alkyl halides to various tertiary phosphine complexes of rhodium(I) and iridium(I) are discussed. Features of interest include (1) an equilibrium between a five-coordinate acetylrhodium(III) cation and its six-coordinate methyl(carbonyl) isomer which is established at an intermediate rate on the NMR time scale at room temperature, and (2) a solvent-dependent secondary- to normal-alkyl-group isomerization in octahedral al-kyliridium(III) complexes. The chemistry of monomeric, tertiary phosphine-stabilized hydroxoplatinum(II) complexes is reviewed, with emphasis on their conversion into hydrido -alkyl or -aryl complexes. Evidence for an electronic cis-PtP bond-weakening influence is presented. 

---