Rhodium, tris

Catalysis by rhodium-tri-H-butylphosphine resulted in high yields of product containing a marked predominance of the a-isomer, which is contrary to the trend expected from a steric point of view. Again, high pressure favored the a-isomer, and 400 atm resulted in a 91% yield of this product. 

Wender et al. have demonstrated the power of the rhodium-catalyzed [5 + 2]-cycload-dition reaction discovered in their laboratories by synthesizing (+)-dictamnol (148) [33], Allenylvinylcyclopropane 145 was treated with rhodium biscarbonyl chloride dimer or rhodium tris(triphenylphosphine) chloride (Scheme 19.27). Both catalysts provided the cycloadduct 146 in 70-76% yield and high diastereoselectivity (8-9 1). The diaster-eoselectivity was attributed to the C8 hydroxyl group assuming a position on the less sterically encumbered exo face of the transition-state structure 147. 

Iridium, trihydrotris(triphenyl-phosphine)-, (0C-6-22)-, 32 307-8 [19584-30-6], Rhodium, tri-carbonylnonacar-bonyltetra-, tetrahedro, 32 284-86 [20000-80-0], l//-Pyrazole-l-ethanol, 3,5-dimethyl-, 32 83-84... 

On adding a warm, concentrated solution of potassium iodide to one of rhodium bromide a black precipitate of Rhodium Tri-iodide, Rhl3, is obtained.2 Dilute solutions give no precipitate in the cold. 

In 1965 Wilkinson invented the rhodium-tris(triphenylphosphine) catalyst as a hydrogenation catalyst [60]. It still forms the basis for many of the chiral hydrogenations performed today. The most effective homogeneous hydrogenation catalysts are complexes consisting of a central metal ion, one or more (chiral) ligands and anions which are able to activate molecular hydrogen and to add the two H atoms to an acceptor substrate. Experience has shown that low-valent Ru,... 

Rli40,2C,2, Rhodium, tri-p-carbonyl-nona-carbonyltetra-, 28 242 RuAsjCljNSCjjHjg, Ruthenium(Il), tri-chloro(thionitrosyl)bis(triphenyl-arsine)-, 29 162... 

Dirhodium terakisformate Rh(HCOO)4(0.5H2O) reacts with thioacetic acid to give rhodium tris(thioacetate), Rh(CH3COS)3. Treatment of the tris(thioacetato) complex with pyridine leads to the adduct 43 Rh2(CH3COS)4(Py)2 [9]. 

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... 

Rh40 2C 2, Rhodium, tri-/(Haabonyl-nona-carbonyltetra-, 28 242 RUB2NBC40H7C, Rutbenium(II), (ir -l,S-cyclooctadiene)tetrakis(methylhy-drazine)-, bis[tetraphenylborate-(1-)], 26 74... 

Jiao Y, Brennessel WW, Jones WD. Oxidative addition of chlorohydrocarbons to rhodium tris(pyrazolyl)borate complex. OrganometaUics. 2015 34 1552-1566. 

In addition to the methods described above, prenol (51) can be prepared from methyl-butynol (43) by rearrangement to prenal (52) using a titanium alkoxide/copper chloride catalyst [69, 70] followed by selective hydrogenation using a ruthenium rhodium tris( 7-sulfonatoyl)phosphine trisodium salt (TPPTS) catalyst [71, 72]. However, it is more usual to prepare the prenyl esters by nucleophilic substitution of a carboxylate anion on prenyl chloride [503-60-6] (56) which, in turn, is available through hydrochlorination of isoprene [78-79-5] (1). This hydrochlorination often employs copper ions as catalysts. These processes are shown in Fig. 8.14. 

Rb40 2Ci2, Rhodium, tri-/i-carbonyl-nona-carbonyltetra-, 28 242 RuB2NgC oH7 , Ruthenium(II), (q -1,5-cyclooctadiene)tetrakis(methyIliy-drazineK bis[tetraphenylborate ... 

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