Copper, alkyl-magnesium

Sultam 53 has proved to be an excellent chiral auxiliary in various asymmetric C-C bond formation reactions. One more example of using sultam 53 is the asymmetric induction of copper(I) chloride-catalyzed 1,4-addition of alkyl magnesium chlorides to a,/ -disubstituted (/ )-enesultams 60. Subsequent protonation of the reaction product gives compound 61c as the major product (Scheme 2-30 and Table 2-11).56... 

Under copper(l) catalysis, excellent yields of dithioesters were obtained at -50°C, and t-alkyl magnesium halides, which led mainly to polymeric products without catalysis, gave yields above 90% in the presence of a catalytic amount (5-10 mol%) of copper(i) bromide [148]. 

The initial drum inventory conducted in 1979 found 17 051 drums on the surface, including 11 628 empty ones. The EPA analyzed the property and creek and found 140 chemical substances. The chemicals found most often and in the highest concentrations were xylene, methyl ethyl ketone, methylene chloride, acetone, phthalates, anthracene, toluene, fluoranthene, alkyl benzene, vinyl chloride, dichloroethylene, and aliphatic acids. Polychlorobi-phenyls were detected in low concentrations and several metals including barium, zinc, copper, strontium, magnesium, and chromium were detected in concentrations exceeding background levels. 

The content of substances which influence the suitability of water for public supply are limited. These include total evaporation residue, total iron, manganese, copper, zinc, magnesium sulphate and sodium sulphate, sodium alkyl benzene sulphonate. 

Alkynyl anions are more stable = 22) than the more saturated alkyl or alkenyl anions (p/Tj = 40-45). They may be obtained directly from terminal acetylenes by treatment with strong base, e.g. sodium amide (pA, of NH 35). Frequently magnesium acetylides are made in proton-metal exchange reactions with more reactive Grignard reagents. Copper and mercury acetylides are formed directly from the corresponding metal acetates and acetylenes under neutral conditions (G.E. Coates, 1977 R.P. Houghton, 1979). 

The regiochcmistry for stoichiometric alkylation with butyl(cyano)copper magnesium bromide is the same as that for the copper cyanide catalyzed reaction. The regiochemistry with dibutyl-copper magnesium bromide is also very similar to that of the copper(I) bromide catalyzed reaction. Lithium cuprates do not exhibit y regioselectivity in this biased system. 

Bromofurans give Grignard reagents when attacked by copper-magnesium in tetrahydrofuran but, while the products can be alkylated, etc., in the expected way, no clear advantage has emerged.225... 

Similarly to the alkyl derivatives, the most common route for arylcopper compounds is the reaction of a copper halide and aryllithium compounds (Equation (4)). Organocuprates with aryl groups are obtained by using an appropriate excess of the lithium reagent. Magnesium aryls have also been employed in transmetallation reactions with Cu(l) salts to yield both arylcopper compounds and arylcuprates (Equations (5) and (6)). 

A mixture of (triisopropyl phosphito)copper(I) bromide (17.6 g, 0.05 mol) and l-bromo-2,2-diphenylethylene (9.1 g, 0.035 mol) was heated at 200°C for 1 h under a nitrogen atmosphere in a flask equipped with a Vigreaux column topped by a Dean-Stark trap. The alkyl halide produced in the reaction was collected in the trap. After cooling, the reaction mixture was poured into toluene (60 ml), and ethylenedi-amine was added (5 ml). After filtering and washing the precipitate with toluene, the combined toluene solutions were washed with 10% hydrochloric acid (10 ml) and water (10 ml), dried over magnesium... 

Synthesis. These macrocycles are prepared from seven-membered ring dinitrile complexes, 84a-84c (Scheme 17), which contain either methylene, sulfur or oxygen in the five position (129). These cyclic dinitriles are synthesized by alkylating maleonitrile dithiolate or derivatives thereof with the corresponding dihalide. The dinitriles 84a-84c can be cyclized in magnesium propoxide to form porphyrazines 85a (33%), 85b (19%), and 85c (27%) (Scheme 17), which can be demetalated with trifluoroacetic to form 86a-86c. Additionally, 86a has been remetalated with nickel (87a, 92%), copper (88a, 95%), and zinc (89a, 94%). The sulfur and oxygen derivatives 85b, 85c, 86b, and 86c are of low solubility and are not suitable for further manipulation. 

As well as alkenylstannanes [106-108], other classes such as a-heteroatom-substituted alkyltributylstannanes [109] and, more importantly, allylic stannanes [110, 111] also undergo these Sn-Cu transmetalations. Otherwise difficult to prepare, allylic copper reagents may, however, be obtained by treatment of allylic stannanes (produced in turn from organolithium, magnesium, or zinc organometallics) with Me2CuLi LiCN. They enter into cross-coupling reactions with alkyl bromides [110] or vinyl triflates (Scheme 2.52) [111]. 

Fuel additives - [AMNES-CYCLOALIPHATIC AMINES] (Vol 2) - [SULFONIC ACIDS] (Vol 23) -arsenic compds as [ARSENIC COMPOUNDS] (Vol 3) -boron compds as [BORON COMPOUNDS - BORIC ACID ESTERS] (Vol 4) -coordination compounds as [COORDINATION COMPOUNDS] (Vol 7) -ethers m [ETHERS] (Vol 9) -magnesium alkyls as [MAGNESIUM COMPOUNDS] (Vol 15) -polyamines as [DIAMINES AND HIGHER AMINES ALIPHATIC] (Vol 8) -htanates as [TITANIUM COMPOUNDS - ORGANIC] (Vol 24) -use of copper compounds [COPPER COMPOUNDS] (Vol 7)... 

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