Oxidative coupling reagents

Ley and co-workers studied the applicability of immobilized phenyliodine(III) bis]acetate) as an oxidative coupling reagent in an effort to develop orchestrated multistep syntheses using... 

Copper(II)-amine complexes are widely used and very effective phenolic oxidative coupling reagents. Since the reaction proceeds within the copper coordinative sphere, chiral amine ligand does induce the enantioselective oxidative couplings of phenols such as 2-naphthol [39-41], or 9-phenanthrol [42,43] to form respective atropisomeric... 

When oxidized by iron(III) ions 4-aminoantipyrine reacts with phenols to yield colored quinonoid derivatives (cf. 4-aminoantipyrine — potassium hexacyanoferrate(III) reagent in Volume 1 a). It is an oxidative coupling based on the Emerson reaction. 

Soluble poly(l-butylperylene) (58) was prepared in very high yields by Anton and Mullen [70] who used the procedure of Taylor [71], which involves the oxidative coupling of bis-Grignard reagents with as-l,4-dichloro-2-butene as an oxidant. The products contain 4,9- and 4,10-perylenylene moieties, are fully soluble and possess average degrees of polymerization of ca. 22. 

In a Kumada-Corriu reaction, an aryl halide is oxidatively coupled with a homogeneous nickel(ll)-phosphine catalyst [2], This species reacts with a Grignard reagent to give biaryl or alkylaryl compounds. Later, palladium-phosphine complexes were also successfully applied. By this means, stereospecific transformations were achieved. 

Triisopropylbenzenesulfonyl)-3-nitro-1,2,4-triazole in the presence of 4-rtiorpholine pyridine-1-oxide was used with advantage as a coupling reagent for a solid-phase (p-alkoxybenzyl ester type resin) synthesis of peptides such as Leu-AIa-Gly-Val-OH or Leu-enkephalinamide (Tyr-Gly-Gly-Phe-Leu-NHs). The overall yield in the latter case was 70%, the purity of the peptide was 85-90%, and racemization was virtually zero.[38]... 

A Sml2-induced reductive cyclization of (V-(alkylketo)pyrroles provided an entry into medium ring 1,2-annelated pyrroles <06EJO4989>. An oxidative radical alkylation of pyrroles with xanthates promoted by triethylborane provided access to a-(pyrrol-2-yl)carboxylic acid derivatives <06TL2517>. An oxidative coupling of pyrroles promoted by a hypervalent iodine(III) reagent provided bipyrroles directly <060L2007>. 

Oxidative coupling of aryl tetrahydroisoquinolines. This reagent is superior to thallium(III) trifluoroacetate or vanadium oxyfluoride for nonphenolic oxidative coupling of substrates such as 2 to provide aporphines and homoaporphines (3). 

Aromatic compounds, 13 108-109 13 680. See also Aromatics acylation of, 12 173-181 amination of, 12 184 arylation of, 12 170-171 Cycloalkylation of, 12 169 in diesel fuel, 12 425 formylation of, 12 178 Friedel-Crafts acylation of, 12 174 Friedel-Crafts alkylation of, 12 164 nitration of, 12 182-183 oxidative coupling of, 19 654 sulfonation of, 12 181 sulfonation reagents for, 23 521-524 Aromatic-containing polymers, sulfonation of, 23 535-536... 

O-ACYL AND A/-ACYL N -OXIDE FORMS OF 1 -HYDROXYBENZOTRIAZOLE ADDUCTS AND THE URONIUM AND GUANIDINIUM FORMS OF COUPLING REAGENTS... 

The terminal phenolic groups of oligomers of poly(2,6-dimethyl-l,4-phenylene oxide), 1, (1, 2) react efficiently with multifunctional coupling reagents to form polymers with increased molecular weights. 

A second method for preparing block copolymers is a crosscoupling process. A low molecular weight coupling reagent is added to a mixture of poly(phenylene oxide) and a second homopolymer with phenolic hydroxyl endgroups such as 7 (9) or 8 (10) in the presence of sodium hydroxide and catalyst. 

Adogen 464, coupling reagent, poly(phenylene oxide), 190 Amination, polymeric organolithium compounds, 139-145... 

The rate of oxidative coupling is said to decrease with decreasing acidity of the ethynyl hydrogen. Thus oct-l-yne underwent only limited reaction after being heated with the reagent under reflux for 24 hours. 

Phenoxyacetophenone, 46, 94 Phenylacetylene, oxidative coupling to diphenyldiacetylene, 46,39 reaction with sodium hypobiomite to yield phenjdbromoethyne, 46, 86 Phenylacetyl fluoride, 46, 6 Phenylbrojioethyne, 46, 86 l-Phenyl-l,3-hutadiene, 46, 94 Phenyl (-butyl ether, 46, 89 />-Phenylene diisothiocyanate, 45, 21 Phenylethynyllithium 46, 88 Phenylethynymagnesium Grignard reagent, 46, 88... 

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