3-Aryl-6- -ones

O-acylation, O-sulfanylation, O-triflation/Suzuki coupling followed by N-quaternization (six inputs) and Hofmann elimination to release a 3,042-member library of tertiary amino aryls. One advantage of small-molecule nonoligomeric libraries... 

Arylation involves the reaction between amines and phenols, aryl halides and aryl amines, including aniline. In arylation, one reactant acts as solvent acidic catalysts and high temperatures are employed. Diphenylamine (A-phenylbenzeneamine, /V-phenylani-line) (8) is made by condensation of aniline in the presence of a small amount of mineral acid catalyst at around 300 °C catalytic reaction of chlorobenzene with aniline at high temperature and pressure and continuous vapor-phase catalytic condensation of aniline. It is a useful intermediate in azo dye manufacture. Crompton is the main US manufacturer of 8, producing 1.3 billion lbs. in 2000. Applications include as lube additives... 

Side reactions are often observed in these intermolecular radical arylations, one major limitation being the slow reaction of the alkyl radical with the arene. The tert-butyl radical addition onto benzene occurs at 79 °C with a rate constant of 3.8 X 10 M s" [103], which is far below the rate constant of an efficient radical reaction. Consequently, side reactions-including rearrangement, dimerization and... 

The Suzuki coupling has also been undertaken utihzing alkenyls instead of aryls. One example of this on the soHd phase is the synthesis of the hormonal, biological form of vitamin D3 and several derivatives [120]. This involved the coupling of a soUd-supported alkenylbromide to two different alkenylboronates (Scheme 45). Further derivatization and cleavage gave 19-nor-la,25-dihydroxyvitamin D3 and three new derivatives. 

Tertiary amines containing one alkyl and two aryl groups, such as mono-I ncthyldiphenyhiniir.e, Cl l3(C, l l.diX , arc rarely encountered and arc unimportant. They usually react with nitrous acid with the insertion of a nitroso group into only one of the two available para positions monomethyl-diphenylamine thus gives monomethyl-mono - pnitroso-diphenylamine. Cl hj(C.ill .)N C l 1 jXO, or V-nicthyl-p-nitrosodiphcnylaniine. 

There is one other benzene to allylbenzene method that you should take a look at. Osmium sent in the article in which that magical clay and other similar catalyst add the allyl to aryl in record fashion. To read more check out ref 143. 

Pd(II) salts promote the carbonylation of organomercury compounds. Reaction of phenylmercury chloride and PdCh under CO pressure affords benzophenone (429)[387]. Both esters and ketones are obtained by the carbonylation of furylmercury(Il) chloride in alcohol[388]. Although the yields are not satisfactory, esters are obtained by the carbonylation of aryl- and alkylmercuryfll) chlorides[389,390]. One-pot catalytic carbonylation of thiophene, furan, and pyrrole (430) takes place at the 2-position via mercuration and transmetallation by the use of PdCb, Hg(N03), and CuCl2[391]. 

The diazonium salts 145 are another source of arylpalladium com-plexes[114]. They are the most reactive source of arylpalladium species and the reaction can be carried out at room temperature. In addition, they can be used for alkene insertion in the absence of a phosphine ligand using Pd2(dba)3 as a catalyst. This reaction consists of the indirect substitution reaction of an aromatic nitro group with an alkene. The use of diazonium salts is more convenient and synthetically useful than the use of aryl halides, because many aryl halides are prepared from diazonium salts. Diazotization of the aniline derivative 146 in aqueous solution and subsequent insertion of acrylate catalyzed by Pd(OAc)2 by the addition of MeOH are carried out as a one-pot reaction, affording the cinnamate 147 in good yield[115]. The A-nitroso-jV-arylacetamide 148 is prepared from acetanilides and used as another precursor of arylpalladium intermediate. It is more reactive than aryl iodides and bromides and reacts with alkenes at 40 °C without addition of a phosphine ligandfl 16]. 

When allene derivatives are treated with aryl halides in the presence of Pd(0), the aryl group is introduced to the central carbon by insertion of one of the allenic bonds to form the 7r-allylpalladium intermediate 271, which is attacked further by amine to give the allylic amine 272. A good ligand for the reaction is dppe[182]. Intramolecular reaction of the 7-aminoallene 273 affords the pyrrolidine derivative 274[183]. 

Acyl halides are intermediates of the carbonylations of alkenes and organic-halides. Decarbonylation of acyl halides as a reversible process of the carbo-nylation is possible with Pd catalyst. The decarbonylation of aliphatic acid chlorides proceeds with Pd(0) catalyst, such as Pd on carbon or PdC, at around 200 °C[109,753]. The product is a mixture of isomeric internal alkenes. For example, when decanoyl chloride is heated with PdCF at 200 C in a distillation flask, rapid evolution of CO and HCl stops after I h, during which time a mixture of nonene isomers was distilled off in a high yield. The decarbonylation of phenylpropionyl chloride (883) affords styrene (53%). In addition, l,5-diphenyl-l-penten-3-one (884) is obtained as a byproduct (10%). formed by the insertion of styrene into the acyl chloride. Formation of the latter supports the formation of acylpalladium species as an intermediate of the decarbonylation. Decarbonylation of the benzoyl chloride 885 can be carried out in good yields at 360 with Pd on carbon as a catalyst, yielding the aryl chloride 886[754]. 

Acetylation of 2-phenyl-4-amino-5-benzoylthiazole takes place on the exocyclic nitrogen (49). This exocyclic nitrogen remains the reactive center even with 2-imino-3-aryl-4-amino-5-carboxamido-4-thiazoline (111). Its acetylation with acetic anhydride gives the 4-acetamido derivative (112), which reacts further on heating to yield 2-(acetylimino)-(3H)-3-aryl-5-methylthiazolo[4,5-d]pvrimidin-7-(6H)-one (113) (Scheme 76) (276). 

Goto et al. (386) have qualitatively studied the relationship between the structure and the ease of formation of some 2-aryl- and 2-heteroaryl-A-2-thiazolin-4-one derivatives. It is found that 2-pyridyI, 2-benzimidazoyl, and 2- 6 hydroxy-5 -methyl)-benzothiazolyl derivatives are too unstable to be isolated. 6 -Hydroxy-, 6 -methyl-, and unsubstituted 2-benzothiazoiyl derivatives, as well as naphtothiazolyl derivatives are unstable but isolable. On the other hand, 6 -methoxy-. 6 -acetoxy-. and 5, 7 -dimethyl-6 -hvdroxybenzothiazolyl derivatives as well as most of their 5-methyl substituted derivatives are stable and easily prepared. 

Aryl-A-2-thiazoline-4-one absorbs at approximately 368 to 381 nm in methanol. The spectrum is unaffected by acidic medium, while in basic medium a large shift toward longer wavelength is observed (386). Other ultraviolet data are given in Refs. 390 and 419. 

The nucleophilic reactivity of the oxygen has been observed in acetylation by acetic anhydride of 2-aryl- and 2-heteroaryl-A-2-thiazoline-4-ones (181) (388, 397, 410, 414, 416, 419, 422, 426. 427) and methylation of 5-(4 -chlorophenyl)-A-2-thiazoline-4-one (416) (Scheme 94). 

A ver promising reactivity of A-2-thiazoline-4-one has been found recently. 5-Aryl-A-2-thiazoline-4-one (190) gives the 1.3-dipolar cycloaddition product (191) with methyl fumarate and methyl maleate... 

For example, p-bromophenacylaryl (or alkyl) sulfides (160) with 157, R] =Et, yield the 5-(aryl or alkyl)-thiothiazolyl-2-ones (161) (Scheme 82) (487). 

For nonsubstituted phenyl thiazoles or for alkylarylthiazoles, one of the problems investigated is the determination of the angle between the aryl and the thiazole rings. In the case of 4,5-diphenylthiazole the problem is complicated by the interaction of the two phenyl rings (126). 

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