0-Aryl compounds, preparation

Heteroleptic chromium aryl compounds, preparation and characterization, 5, 298 Heteroleptic compounds actinide complexes, 4, 193 lanthanide complexes, 4, 7... 

Homoleptic chromium aryl compounds, preparation and characterization, 5, 298... 

By use of aryl compounds prepared in this way, the arylation of alkenes and a variety of other organic unsaturated compounds can be achieved.52 A palladium compound, usually Li2PdCl4, is used as a transfer agent and organopalladium species are believed to be unstable intermediates by use of air and a Cu" salt the reaction can be made catalytic, since the Pd metal formed in the reaction is dissolved by Cu11 and the Cu1 so produced is oxidized by air (cf. the Wacker process, Section 24-B-5). A typical reaction is... 

Dienes and allylarcncs can be prepared by the Pd-catalyzcd coupling of allylic compounds with hard carbon nucleophiles derived from alkenyl and aryl compounds of main group metals. Allylic compounds with various leaving groups can be used. Some of them are unreactive with soft nucleophiles, but... 

The aryl compounds are unstable substances which decompose on standing and are hydrolyzed ia moist air. The chlorides are readily prepared by the actioa of hydrochloric acid oa the corresponding arylstibonic acids. Tetraacetatopheaylantimoay [116122-86-27], C24H2yOgSb, has beea prepared (168) ... 

The present synthesis10 consists of two simple steps, uses readily available and inexpensive starting materials, and produces pure material in high overall yield. It is based on two observations that nonenolizable ketones may be cleaved to carboxylic acids by potassium ferf-butoxide-water,2 and that aryl 2 chlorophenyl ketones may be cleaved with loss of the 2-chlorophenyl group to give only one of the two possible acids.11 Other compounds prepared by this route include carboxycyclopentadienyltriearbonylmanganese [Manganese, tricar-bonyl[(l, 2,3,4,5- )-l-carboxy-2,4-cyclopentadien-l-yl]-] (79%)10 and... 

In the presence of a precious metal catalyst, aryl halides can undergo dehalo-dimerization to give biaryl products, with varying degrees of selectivity. The major byproduct of this reaction is usually the dehalogenated aryl compound. This type of chemistry is currently one of the very few viable means for the large scale preparation of biaryl compounds. 

AstraZeneca has filed a patent application on novel bis-aryl compounds as CB1/CB2 agonists that lack CNS penetration and thus avoid the unwanted side effects associated with activation of central CBi receptors [210]. Over 100 compounds are specifically claimed e.g. (321). Compounds were tested in receptor binding assays using human CBi and CB2 receptor preparations. Respective K values were in the ranges 50-5,000 and 15-2,800 nM, although no specific data were presented. 

In this section, functionalized aryl and heteroaryl compounds prepared by arene-catalyzed lithiation will be considered. 

Functionalized aryl Grignard compounds, prepared by iodine-magnesium exchange according to the procedure reported by Cahiez, Knochel and coworkers in 1998, can be efficiently acylated. It is thus possible to prepare various polyfunctionalized diaryl ketones (Scheme 14). ... 

Unsubstituted phosphino- and arsino-dithioformic acids and their dithioformates have not yet been described. In addition, the monosubstituted primary alkyl and aryl compounds have not been investigated very well. Disubstituted phosphinodithioformates can be prepared easily. Because of the difference in basicity of Ph2PH and Et2PH they react with CS2 in different ways (reactions 14 and 15). By addition of metal ions to the resulting ethyl compound, one CS2 is split off.1 Only the potassium complexes have a second CS2 molecule bonded to the phosphorus atom. 

The yield increases with aryl-compounds, as may be seen from the two following preparations. 

Homoleptic germylenes, preparation and properties, 3, 773 Homoleptic lanthanide(II) alkyl compounds, properties, 4, 4 Homoleptic manganese aryl complexes, preparation, 5, 816 Homoleptic manganese isonitrilates, preparation, 5, 773—774 Homoleptic molybdenum complexes, preparation and characteristics, 5, 514... 

Calcium has received some application in organic synthesis similar to that of magnesium alkyl and aryl compounds, CaRa, have been prepared, and it seems likely that many of the magnesium syntheses, already mentioned, could be accomplished by the use of calcium. 

Palladium catalysed coupling reaction of a heteroaromatic zinc compound with a functionalized aryl iodide preparation of N-benzyl-6-(4-ethylcarboxyphenyi)-purine33... 

In the same way catenated stannyl, germyl silanes were prepared (equation 125)105. The structure of an aryl compound was resolved by X-ray analysis105. 

We applied these optimized conditions with aryl bromide 38. Bromide 38 was prepared from isophthalic acid by bromination in the meta position with concentrated sulfuric acid, bromine and silver sulfate to give compound 37,34 which was converted to the isopropyl ester with HMPA and isopropyl iodide (Scheme 14). When 5-bromo-isophthalic acid diisopropyl ester 38 was treated with diphenethylamine only starting material and reduced aryl compound... 

Some aryl- and aroyl-aminofuroxans and bis(dialkylamino)furoxans have been reported. 4-Amino-3-methylfuroxan has been prepared by hydrolysis of its O-benzylurethane. The 4-amino-3-aryl compounds can be acylated but the 3-amino-4-aryl isomers appear to be less reactive. On oxidation with hydrogen peroxide 3-aryl-4-nitrofuroxans are formed. The nitro group can be displaced by nucleophiles (see Section 4.22.3.2.4) or reduced back to the amino group using tin(II) chloride. 

Examples of aryl elhenyl tellurium compounds prepared in this manner are given in Table 12 (p. 403). 

Ethoxycarbonyl)-ethen-l-yl aryl telluriums were similarly hydrolyzed without affecting the tellurium atom or the carbon-carbon double bond6,7. The free acids were isolated as sharp-melting solids in yields ranging from 60 to 95%. Examples of compounds prepared in this manner are ... 

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