Carbonyl compounds copper bromide

In order to modulate the reactivity of intermediate 331, it was transformed into its copper derivative by treatment with copper(I) bromide or iodide in THF at —78 °C, and then was allowed to react with a,/3-unsaturated carbonyl compounds (to give compounds 343 resulting from a conjugated addition), acyl chlorides (to give ketones 344) and copper(II) chloride (to dimerize giving compounds 345) (Scheme 100)"° ". ... 

Triorganylbismuthines can mediate such C-C bond forming reactions as shown in Scheme 5.38 in the presence or absence of a transition metal salt. Tributylbismuthine promotes the allylation of carbonyl compounds with allylic bromide [91HAC297] and the olefination of diazo compounds with carbonyl compounds in the presence of catalytic amounts of a copper(I) halide [90TL5897]. A combination of triphenylbismuthine and WCle promotes the metathesis of olefins, while a similar combination with TiC facilitates the stereoselective Diels-Alder reaction of unsaturated esters [76TMC183, 93JOC4783]. 

Aldol synthesis. A new synthesis of 3-hydroxy ketones and esters involves regiospecific conversion of an a-bromo ketone or ester into an aluminum enolate by a coupled reaction with diethylaluminum chloride and zinc activated with copper(I) bromide in THF at —20°. This enolate adds to carbonyl compounds to give, after work-up, j3-hydroxy ketones (equation I). 

Recently, Sarangi et al. (1995) discovered that the Barbier-type allylation of carbonyl compounds could be mediated by zero-valent copper. In the experimental procedure copper(ll) chloride in its hydrated form was mixed with magnesium powder. This reaction did not proceed with anhydrous CuCU, but addition of water to this anhydrous salt in the presence of magnesium allowed the allylation of aldehydes and ketones with allylic bromides. In the absence of halides, the hydrated reagent (CuCl2 2H20/Mg) turned out to be efficient in the reduction of aldehydes. However, the water of crystallization could not suffice and addition of water promoted the reduction process (Sarangi eta/., 1995). 

Oxidation of Alcohols. Alkoxymagnesium bromides of secondary alcohols and allylic and benzyhc alcohols are oxidized to the corresponding ketones or aldehydes with N-chlorosuccinimide in the presence of r-BuOLi. The method is ineffective for primary saturated and some unsaturated alcohols, but oxidations of the former substrates to aldehydes occur readily if t-butoxymagnesium bromide is substituted for f-BuOLi. Secondary alcohols (eq 2) and primary benzylic (eq 3) and allylic alcohols are oxidized to the corresponding carbonyl compounds in good yields using 2—3 equiv of a 1 1 mixture of copper(II) bromide—r-BuOLi in THF at rt. However, the reagent is not effective for the conversion of primary aliphatic alcohols to aldehydes. 

In the carbonylation reactions, further reaction of the acyl lithium compounds with carbon monoxide can occur, but clean reaction can be achieved if the lithium amide is first converted to a copper derivative (Scheme 130) (79JOC3734). In the case of morpholine, reaction with allyl bromide gave a 93% overall yield of the amide product. 

Synonym Neatsfoot Oil Necatorina Nechexane Neutral Ahhonium Pluoride Neutral Anhydrous Calcium Hypochlorite Neutral Lead Acetate Neutral Nicotine Sulfate Neutral Potassium Chromate Neutral Sodium Chromatetanhydrous Neutral Verdigris Nickel Acetate Nickel Acetate Tetrahyorate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Hexahydrate Nickel Bromide Nickel Bromide Trihydrate Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Iiu Fluoborate Nickel Fluoroborate Solution Nickel Fluoroborate Nickel Formate Nickel Formate Dihyorate Nickel Nitrate Nickel Nitrate Hexahydrate Nickel Sulfate Nickel Tetracarbokyl Nickelous Acetate Nickelous Sulfate Nicotine Nicotine Sulfate Nifos Nitralin Nitram O-Nitraniline P-Nitraniline Nitric Acid Nitric Acid, Aluminum Salt Nitric Acid, Iron (111) Salt Compound Name Oil Neatsfoot Carbon Tetrachloride Neohexane Ammonium Fluoride Calcium Hypochlorite Lead Acetate Nicotine Sulfate Potassium Chromate Sodium Chromate Copper Acetate Nickel Acetate Nickel Acetate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Nickel Bromide Nickel Bromide Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Fluoroborate Nickel Fluoroborate Nickel Fluoroborate Nickel Formate Nickel Formate Nickel Nitrate Nickel Nitrate Nickel Sulfate Nickel Carbonyl Nickel Acetate Nickel Sulfate Nicotine Nicotine Sulfate Tetraethyl Pyrophosphate Nitralin Ammonium Nitrate 2-Nitroaniline 4-Nitroaniline Nitric Acid Aluminum Nitrate Ferric Nitrate... 

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