Carbonylations tetrakis palladium

The oxidative addition is quite general with alkyl, allyl, benzyl, vinyl, and aryl halides as well as with acyl halides to afford the palladium (II) complex VII. The frans-bis( triphenylphosphine )alkylpalladium halides can also be carbonylated in an insertion reaction to give the corresponding acyl complexes, the stereochemistry of which (17, 18) proceeds with retention of configuration at the carbon bonded to palladium. The acyl complex also can be formed from the addition of the corresponding acid halide to tetrakis (triphenylphosphine) palladium (0). 

Lithium diisopropylamide, 163 Phenyliodine(III) diacetate, 242 Tetrakis(triphenylphosphine)-palladium(O), 289 Trimethylamine N-oxide, 325 Containing one nitrogen—indoles Hexamethyldisilazane-Chlorotri-methylsilane, 141 Iron carbonyl, 152... 

More recently, methods based on the use of mild reductants, able to transfer a single electron to the polyhaloalkyl halide, have been described. Various metals or their derivatives have been employed ruthenium, platinum and their complexes in low oxidation state, iron" and its carbonyl complexes, or tetrakis(triphenylphosphane)palladium. Sodium arcncsul-finate, sodium dithionite" and various oxidants have also been used. Other examples of polyhaloalkyl halide additions to simple alkenes are summarized in Table 1. Typical examples are the formation of diiodide 6, chloro iodide 7, and iodo steroid 8. ... 

Reduction of acid chlorides to aldehydes One of the most useful synthetic transformations in organic synthesis is the conversion of an acid chloride to the corresponding aldehyde without over-reduction to the alcohol. Until recently, this type of selective reduction was difficult to accomplish and was most frequently effected by catalytic hydrogenation (the Rosenmund reduction section 6.4.1). However, in the past few years, several novel reducing agents have been developed to accomplish the desired transformation. Among the reagents that are available for the partial reduction of acyl chlorides to aldehydes are bis(triphenylphosphine)cuprous borohydride , sodium or lithium tri-terf-butoxyaluminium hydride, complex copper cyanotrihydridoborate salts °, anionic iron carbonyl complexes and tri-n-butyltin hydride in the presence of tetrakis(triphenylphosphine)palladium(0). ... 

Using a strategy of lactam synthesis with a combination of carbonylation and nitrogenation, 2-methyl- and 2-benzylquinazolin-4(3i/)-one 17 are obtained in 54 and 40% yield, respectively, on treatment of corresponding 2-bromoacetanilides 16 with tetrakis(triphenylphosphane)-palladium [Pd(Ph3P)J, potassium carbonate, and a titanium isocyanate complex in A-methyl-pyrrolidone under a carbon monoxide atmosphere. ... 

When 3,3-dimethylcyclopropene is exposed to carbon monoxide under pressure in the presence of tetrakis(triphenylphosphane)palladium as catalyst, 3,3,6,6,10,10-hexamethyl-exo,enrfo-tet-racyclo[7.1.0.0 " .0 ]decan-8-one (hexamethyl-tris-cr-homotropone, 10) is formed as the main product (72.2%) along with carbonyl-free di- and oligomerization products. At ambient pressure with an in situ generated palladium(O) catalyst, only a 20% yield of the tetracyclic ketone 10 is obtained. 

Enol ethers of alkyl cyclopropyl ketones are alkylated or carboxylated under the correct conditions. Methyl ann, c ,cw-2,9,9-trimethyl-5-trifluoromethylsulfonyloxytricyclo[5.3.0.0 " ]dec-5-ene-4-carboxylate on treatment with palladium(II) acetate in methanol containing triethylamine under a carbon monoxide atmosphere resulted in diester formation giving dimethyl fln ,c .5,cw-2,9,9-trimethyltricyclo[5.3.0.0 ]dec-5-ene-4,5-dicarboxylate in excellent yield (93%). The same substrate was converted to methyl anr/,cw,d. -5-formyl-2,9,9-trimethyltricyclo[5.3.0.0 ]dec-5-ene-4-carboxylate in 88% yield on carbonylation in the presence of tetrakis(triphenylphosphane)palladium, tributyltin hydride, and lithium chloride. ... 

Palladium-catalyzed carbonylation of aryl triflates in the presence of an alcohol141 or amine1423 provides a good method for preparation of arenecarboxylic esters and amides from phenols (equation 121). However, palladium-catalyzed cyanation of 5,6,7,8-tetrahydro-2-naphthyl triflate with potassium cyanide failed completely whereas the more reactive tetrakis(triphenylphosphine)nickel(0) could catalyze the same reaction which gives the nitrile in a good yield142b (equation 122). 

Attention now turned to the installation of the carbonyl moiety. First, carbon-ylation of iodide 45 with bis(triphenylphosphine)palladium(II) dichloride and hydrazine at 60 °C was investigated (Entry 1, Table 4). After 30 min, the starting material had been fully consumed, furnishing a low yield of an unidentifiable product, and potentially formed via reaction of hydrazine with the carbonyl moiety. In contrast, application of high temperature carboalkoxylation conditions was successful (Entry 2). Carboalkoxylation with carbon monoxide catalyzed by palladium tetrakis(triphenylphosphine) with... 

O12OS4C12H4, Osmium, dodecacarbonylte-tra- i-hydrido-tetrakedro-tetra-, 28 240 O12OS4S2C12, Osmium, dodecacarbonyldi- i,-thio-tetra-, 26 307 Oi2P4PdC24H o> Palladium(0), tetrakis-(triethyl phosphite)-, 28 105 Oi2P4PtC24Hgo, Platinum(0), tetrakis-(triethyl phosphite)-, 28 106 Oi2Rh4C]2, Rhodium, tri-f(-carbonyl-nona-carbonyltetra-, 28 242... 

One of the most interesting and useful applications of phase transfer catalysis in organometallic chemistry is the catalytic carbonylation reaction of alkyl halides [50]. Palladium tetrakis triphenylphosphine catalyzes the carbonylation of benzyl chloride in a two phase system containing xylene and aqueous sodium hydroxide according to equation 9.21. Phenylacetic acid (4000 moles/mole Pd) is produced in... 

The elimination of benzoic acid from the benzyloxycarbonyl compounds (206) is catalysed by tetrakis(triphenylphosphine)palladium, giving ( , )-dienoic carbonyl compounds (207). ... 

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