Molybdenum complexes dimethyl

When methylene chloride was used as a solvent, it was found that 28 are obtained in minor amounts, while the dominating product is the -coordinated chloro-carbyne species [(> -Tp )Mo(CO)2(=CCl)], whose yield increases abruptly with substitution in the pyrazol-l-yl fragments (3-methyl-, 3,4,5-trimethyl-, and 3,5-dimethyl-4-chloro derivatives) [90AX(C)59,95JCS(D) 1709]. The tungsten analog can be prepared similarly. The chlorocarbyne molybdenum complex follows also from the reaction of the parent anion with triphenylsulfonium cation but conducted in dichloromethane. The bromo- and iodocarbyne derivatives are made similarly. 

The 3,4-dimethyl-l-phenylphosphole (the so called Mathey-phosphole ) entered into Friedel-Crafts acylation only through its molybdenum complex (20). Elimination of the Mo(CO)5 moiety from product 21 furnished 2-acylphosphole 22 (.Scheme 5) [42],... 

Dimethyl-diaminobutane, cobalt(lU) hexa-amines, 35 130-131, 155-156 Dimethyldiazidosilane, preparation, 9 138 Dimethyldivinylsilane, molybdenum complex of, 4 83... 

As described in many reviews, Trost and his co-workers have carried out a pioneering work on the molybdenum-and tungsten-catalyzed allylic alkylation of allylic esters regioselectivity of the reaction is often complementary to the palladium-catalyzed allylic alkylation. The first asymmetric version was disclosed by Pfaltz and Lloyd-Jones in 1995 (Equation (63)). They used a catalytic amount of a novel tungsten complex, prepared from [W(CO)3(MeCN)3] or [W(cycloheptatriene) (COIs] and optically active (diphenylphosphino)phenyloxazolines 57, for the allylic alkylation of 3-aryl-2-propenyl phosphate with dimethyl sodiomalonate to isolate the corresponding branched alkylated compounds as a major isomer with an excellent enantioselectivity (96% ee). Unexpectedly, 3-aryl-2-propenyl carbonates are shown to be unreactive. It is worth noting that an isostructural molybdenum complex does not promote the catalytic alkylation under the same reaction conditions. In contrast, Lloyd-Jones and Lehmann reported the stereocontrolled... 

More recently, a new molybdenum complex, oxodiperoxymolybdenum-pyridine 3,4,5,6-tetrahydro-1,3-dimcthyl-2-(l //)-pyrimidinonc (MoOs py DMPU = MoOPD) has been introduced in which 1,3-dimethyl-3,4,5,6-tetrahydro-2(lf/>pyrimidinone (DMPU) is used as a non-carcinogenic alternative to HMPA54. This reagent offers comparable results to MoOPH reagent in the oxygenation of enolates (Table 4). 

AsAgFsSi6, Arsenate, hexafluoro-, bis-(cycZo-octasulfur)silver(l -h), 24 74 AsBrsFgS, Arsenate, hexafluoro-, tribromo-sulfur(IV), 24 76 AsQH, Arsine, dimethyl-molybdenum complex, 25 169 AsCigHis, Arsine, triphenyl-chromium complexes, 23 38 ASC24H10, Arsonium, tetraphenyl-... 

QH P, Phosphine, dimethylphenyl-, iron complex, 26 61 molybdenum complex, 27 11 osmium complex, 27 27 osmium-rhodium complex, 27 29 osmium-zirconium complex, 27 27 ruthenium complex, 26 273 CkH,2, 1,5-Cyclooctadiene, iridium complex, 26 122, 27 23 osmium-rhodium complex, 27 29 ruthenium complexes, 26 69-72, 253-256 CbH 20,PS, 2-Butenedioic acid, 2-(dimeth-ylphosphinothioyl)-, dimethyl ester, manganese complex, 26 163 ChH,4, Cyclooctene, platinum complex,... 

NSC, Thiocyanate, gold complex, 26 90 NS2C5H11, Dithiocarbamic acid, diethyl-, molybdenum complex, 28 145 NSiC,H , Ethanamine, 1,1-dimethyl-A -(trimethylsilyl)-, 27 327 NSi2C4H , Silanamine, 1,1,1-trimethyl- -(trimethylsilyl)-, ytterbium complex, 27 148... 

OgNjCigHig, Acetic acid (1,2-ethanediyl-dinitTilo)tetra-, molybdenum complexes, 29 256,259 OgNiP4C32H44, Nickel(0), Tetrakis(dimethyl phenylphosphonite)-, 28 101... 

Isopropenyl groups are relatively unreactive towards metathesis. 2,5-Dimethyl-hexa-1,5-diene, with an isopropenyl group at both ends, does not react at all in the presence of either 8 or 17. However, while 2-methylhexa-1,5-diene reacts only at the vinyl end in the presence of the tungsten complex 17, to give the dimer (n = 2 in Table 8.1), the corresponding molybdenum complex 8 is much more active and the end product is perfectly head-tail 1,4-polyisoprene, formed by alternate reactions of an isopropenyl groups with [Mo]=CH2 and of a vinyl group with [Mo]=CMeP where P is the polymer chain (Konzelman 1995). 

Molybdenum tungsten hydroxide oxide phosphate, compd. with ethyl 2-(6-ethylamino)-3-(ethylimino)-2,7-dimethyl-3H-xanthen-9-yl) benzoate. See Pigment red 81 Molybdenum white. See Calcium-zinc-molybdenum complex Zinc molybdate Molybdic acid, ammonium salt, tetrahydrate. 

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