Allyl phenyl ether preparation

The Pd-catalyzed elimination reaction was applied to the synthesis of 12-acetoxy-l,3-dodecadiene, an insect sex pheromone from the red bollworm moth, by elimination of phenol with Pd(OAc)2 and P(OPh)3 at 160 °C under reduced pressure (1 torr) from the allyl phenyl ether prepared from a butadiene telomer (Scheme... 

Allyl phenyl ether is prepared by the reaction of phenol with allyl bromide, as described in Section 24.11. 

It is well known in the literature that one of the best procedures to prepare allyllithium is the lithiation of allyl phenyl ethers . This reaction can be easily induced when a pinch of biphenyl was introduced at the beginning of the process . 

A series of pyrido[2,3-rf pyrimidine-2,4-diones bearing substituents at C-5 and/or C-6 were synthesized using palladium-catalyzed coupling of uracil derivative 417 with vinyl substrates or allyl ethers to give the regioisomeric mixtures of 418/419 and 420/421, respectively. The ratio of the isomeric structures was dependent on the substituent R. In the case of the reaction with -butyl vinyl ether, only the product 419 was obtained. However, the reactions with acrylonitrile, ethyl acrylate, 2-trifluoromethylstyrene, and 3-nitrostyrene afforded only 418. Also, reaction with allyl phenyl ether gave only 420. The key intermediate 417 was prepared by the reaction of 6-amino-l-methyluracil with DMF-DMA (DMA = dimethylacetamide), followed by N-benzylation with benzyl chloride and vinyl iodination with iV-iodosuccinimide (NIS) (Scheme 15) <2001BML611>. 

Preparation of Allyl Phenyl Ether, f A mixture of 188 g. of phenol, 242 g. of allyl bromide, 280 g. of finely ground calcined potassium carbonate, and 300 g. of acetone is refluxed on the steam bath for eight hours. A heavy predpitate of potassium bromide begins to form soon after the refluxing is started. After cooling, water is added the product is taken up in ether and washed twice with 10% aqueous sodium hydroxide solution. The ether solution is dried over potassium carbonate, and, after removal of the ether, the residue is distilled under diminished pressure. The yield is 230 g. (86%), b.p. 85°/19 mm., dll 0.9845. The residue is so small (6 g.) that the distillation might be omitted unless a very pure product is desired. About 1% of allyl 2-allylphenyl ether (a product of C-alkylation) is formed by this procedure. 

Preparation of Allyl Phenyl Ether, t A mixture of 188 g. of phenol,... 

Cleavage of ethers also can be brought about by carriers of alkali metals, such as sodium naphthalenide. For example, allyl Na is preparable in 50% yield by cleavage of allyl phenyl ether by Na naphthalenide in THF at — 20°C ... 

A convenient new method of preparing the reagent is by cleavage of allyl phenyl ether with lithium in tetrahydrofurane. ... 

The preparative Claisen rearrangement was studied in aqueous media at temperatures up to 300 °C. The experiments were conducted in the recently created pressurized microwave batch reactor and in conventional heated autoclaves. It was found that allyl phenyl ether isomerizes in water during 10 min at 240 °C to give the ortho-Claisen rearrangement product in 84% conversion . 

Alkenes (e.g. camphene) are readily prepared by the BF3,Et20-catalysed elimination of secondary borate esters.Terminal conjugated dienes may be prepared by Pd(OAc)2-PPh3-catalysed elimination from allyl phenyl ethers or allylic acetates [e.g. geranyl, neryl, and linalyl acetates to form similar mixtures of myrcene (60—74%), trans-ocimene (8—20%), and c -ocimene (14—20%)], and the complex [(i7-CsH5)Cr(NO)2]2 dehalogenates n/c-dihalides (e.g. limonene tetrabromide) without affecting other halides (except for benzyl halides). 

Palladium-catalysed hydrogenolysis of allylic acetates and allylic phenyl ethers with ammonium formate provides a convenient method of preparation of 2-olefins [equation (5)]. The preferred catalyst is the readily available complex... 

Claisen Rearrangement—Preparation of Allyl Phenyl Ether and Its Rearrangement to 2-Allylphenol (4,5]... 

S-1. Preparation of Triphenylmethyl Ethyl Ether 5-2. Preparation of Allyl Phenyl Ether... 

The usefulness of the Claisen rearrangement in synthetic work depends on the following facts. The allyl aryl ethers, such as phenyl allyl ether (LX), can be prepared easily in high yields and can be transformed readily in good yields to the 2-allylphenols (LXI). The reaction thus... 

The highest diastereoselectivity of asymmetric methoxyselenenylation of alkenes was achieved using the ferrocenylselenium triflates in excellent chemical yields [5gj. For example, the stoichiometric reaction of the chiral ferrocenylselenium triflate 41, prepared from the chiral diferrocenyl diselenide 2, with traus- -methylstyrene afforded the corresponding methoxyselenenylated product in high chemical yield with excellent diastereoselectivity (up to 98 % de). Fukuzawa and co-workers employed the diferrocenyl diselenide 2 for the catalytic asymmetric oxidation of, y-unsaturated esters and traus- -methylstyrene to the corresponding optically active allylic methyl ethers with moderate enantio-selectivity (Scheme 24) [27]. The allylic ethers were produced from 4-phenyl-3-butenoic acid esters in 70-78% yield with 17-22% ee. 

As mentioned in the discussion of the pathways to indoles (Scheme 27), a detailed indole synthesis with two points of diversity based on the Heck reaction has been reported [164]. The indole core structure was synthesized via a 5-exo-tng transition state, which provided the exocyclic double bond that subsequently underwent exo to endo double-bond migration. The anthranilate building block was prepared in solution and immobilized by a method previously described for the loading of 2-aminobenzophenones [Ij. After Fmoc cleavage, the resulting 4-bromo-3-amino-phenyl ether was treated with acid chlorides and pyridine in CH2CI2. As outlined in Scheme 29, alkylation of the anilide with substituted allyl bromides was achieved in the presence of lithium benzyloxazoHdinone in THF. The reaction mixture was treated with base for 1 h and then an aUylic halide was added and the mixture was vortexed for 6 h at room temperature. The alkylation reactions were... 

Allylsilanes are prepared from allyl ethers (silyl ethers or phenyl ethers) and RsSiCl coupling takes place in the presence of Pd(acac)2 and PhMgBr (240 mol%). ... 

Preparation of allyl phenyl ether756 serves as example of Claisen s method of etherification A mixture of phenol (188 g), allyl bromide (242 g), finely powdered potassium carbonate (280 g), and acetone (300 ml) is heated on the water-bath under reflux for 8 h. Potassium bromide separates. After cooling, the mixture is treated with water and extracted with ether. The ethereal solution is shaken with 10% sodium hydroxide solution, dried over potassium carbonate, and evaporated. Distillation of the residue in a vacuum gives the ether (230 g, 86%), b.p. 85°/19 mm. 

Fission of aryl ethers can also be effected by metallic sodium or potassium. For instance, diphenyl ether, which is one of the most resistant ethers, is decomposed by liquid potassium-sodium alloy at room temperature.38 Weber and Sowa have cleaved 4,4 -disubstituted diphenyl ethers into benzene and phenol derivatives by sodium in liquid ammonia.39 Diallyl ether is converted by sodium dust at 35° into allylsodium and sodium allyl oxide, which provides a suitable method for preparation of allylsodium.3 7a Anisole, phenetole, benzyl phenyl ether, and diphenyl ether give the phenols in 90% yield, without by-products, when boiled with sodium or potassium in pyridine.40... 

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