F Allyl vinyl ether

Allyl 4-toluenesulfonate, 3315 f Allyl vinyl ether, 1904 f 3-Aminopropene, 1254 3-Azidopropene, 1188 f l-Bromo-2-butene, 1548 f 3-Bromo-l-propene, 1153 /V-Chloroallylaminc. 1202 l-Chloro-4-(2-nitrophenyl)-2-butene, 3270 f 3-Chloropropene, 1158 f 3-Cyanopropene, 1465 f Diallylamine, 2450 f Diallyl ether, 2431... 

The organoaluminum-promoted Claisen rearrangement139 of allyl vinyl ethers such as (f )-( )-6-methyl-4-vinyloxy-2-heptenc leads preferentially to Ry(E)- or (S)-(Z)-1 depending on the reagent employed 14°. The rearrangement products have been assigned by correlation (see p 437). i... 

Ethanolamine perchlorate, see 2-Hydroxyethylaminium perchlorate, 0947a f Ethanoyl chloride, see Acetyl chloride, 0731 Etheneamine, see Vinylamine, 0860 f Ethene, see Ethylene, 0777 Ethenone, see Ketene, 0718 f 3-Ethenoxypropene, see Allyl vinyl ether, 1898 Ethenylbenzene, see Styrene, 2940 f Ethenyl ethanoate, see Vinyl acetate, 1527 f Ethenyl methanoate, see Vinyl formate, 1146 A-Ethenyloxybenzenecarboximidamide, 3142b f Ethenyltrichlorosilane, see Trichlorovinylsilane, 0743 4-Ethoxybutyldiethylaluminium, 3366... 

Claisen rearrangement.1 Allyl vinyl ethers such as 3 undergo Claisen rearrangement reluctantly and in low yield when treated with methylaluminum bis(2,6-di-f-butylphenoxide), MAD but this dibromo derivative, 1, effects this rearrangement readily at -78° with high (Z)-selectivity. Evidently the bulky r-butyl groups control the stereoselectivity, for use of methylaluminum bis(2,6-diphenylphenox-... 

A series of c/s-substituted allyl-a-trimethylsilylvinyl ethers was also investigated with the same catalyst (f )-98 [25,26]. The data in Table 3 reveal that the enantiomeric purity of the product obtained from asymmetric Claisen rearrangement of the cis-allyl vinyl ethers 104 is not quite as high as from that of the corresponding trans-allyl ethers 102. It was, however, surprising to find that the cis and tram isomers both gave the same enantiomer of the product for all the substrates in Table 3. 

An improved ligand design by Manioka, Saito and Yamamoto has led to a catalyst that is effective for allyl vinyl ethers that are unsubstituted on the vinyl group [27]. This was a serious limitation of the BINOL-derived catalyst 98 which induced only C-O bond cleavage with these substrates (Table 1, entry 1). The ligand (f )-115 was prepared in six steps from (/ )-BINOL and was reacted with trimethylaluminum to give C3 symmetrical Lewis acid Five substituted catalysts were prepared and as... 

Several chiral organoaluminum Lewis acids catalyze the Claisen rearrangement of achiral allyl vinyl ethers to furnish chiral (3, y-unsaturated aldehydes with good enantioselectivity. Among the most effective catalysts is ATBN-F, a chiral aluminum tris(P-naphthoxide) species prepared from enantiomerically pure binapthol. ... 

Ethenone, 5ee Ketene, 0722 f 3-Ethenoxypropene, see Allyl vinyl ether, 1904... 

Asymmetric Claisen Rearrangement of Allylic Vinyl Ethers with Chiral Organoaluminum Reagent (/f)-l or (5)-l (Ar = C6H5) General Procedure138 ... 

The Claisen rearrangement of disubstituted allyl vinyl ether 24 was expected to proceed via to a chair-like transition state D because of favorable less-hindered geometry (Eq. 3.1.28) [35]. The importance of the favorable steric control elements found in D to the excellent stereochemical complementary can best be emphasized by comparison with the rearrangement of 26 bearing the E allyl ether under the same reaction conditions as that of 24 (Eq. 3.1.29). In this case, 25% of the aldehydic product mixture arises by way of boat-like transition state E because it is rather less crowded than F. 

The 6,7-dihydro-5/f -1,4-dioxepin (266) has been prepared (54CR(38)982). and more recently it has been shown that the 2,3-dihydro-5jF/-l,4-dioxepins (263) and (265) can be produced from 1,4-dioxine-halocarbene adducts (264), either by heating under reflux in xylene or by treatment with bases. The allylic chlorine atom in (263) is readily substituted by alkoxide or cyanide ions (77ZC331, 76UKZ968). Saturated rings of type (267) have been prepared by the treatment of cyclic acetals of ethane-1,2-diol with vinyl ethers in the presence of boron trifluoride, and l,4-dioxepan-5-one (268) has been prepared by the reaction of bromoform and silver nitrate with aqueous dioxane (60AG415). 

Partially fluorinated vinyl ethers of fluoroolefins are quite susceptible to the action of Lewis acids. Reaction usually proceeds with ionization of the allylic C-F bond and results in formation of C=0 group and elimination of alkyl halide. Indeed, 3-chloro-2-methoxyhexafluoro-2-butene 82 reacts with A1C13 with formation of trichlorovinyl ketone 83, and cyclic alkoxyfluoroalkenes demonstrate similar behavior in reaction with aluminum or tin(IV) halides [170] ... 

Allylic double bonds can be isomerized by some transition metal complexes. Isomerization of alkyl allyl ethers 480 to vinyl ethers 481 is catalysed by Pd on carbon [205] and the Wilkinson complex [206], and the vinyl ethers are hydrolysed to aldehydes. Isomerization of the allylic amines to enamines is catalysed by Rh complexes [207]. The asymmetric isomerization of A jV-diethylgeranylamine (483), catalysed by Rh-(5)-BINAP (XXXI) complex to produce the (f )-enaminc 484 with high optical purity, has been achieved with a 300 000 turnover of the Rh catalyst, and citronellal (485) with nearly 100% ee is obtained by the hydrolysis of the enamine 484 [208]. Now optically pure /-menthol (486) is commerically produced in five steps from myrcene (482) via citronellal (485) by Takasago International Corporation. This is the largest industrial process of asymmetric synthesis in the world [209]. The following stereochemical corelation between the stereochemistries of the chiral Rh catalysts, diethylgeranylamine (483), diethylnerylamine (487) and the (R)- and (5)-enamines 484... 

Formation of vinylic (trigonal C-Li), allylic or benzylic organolithiums a to O is more favourable. The useful acyl anion equivalent methoxyvinyllithium 11, for example, is formed on treatment of methyl vinyl ether with f-BuLi at -65 °C,13 and furan is lithiated by BuLi in Et20 at 0 °C to give 12.14 More complex carbohydrate-derived vinyl ethers such as 13 also lithiate readily.15... 

For benzoic acid acceleration in Yb(OTf)3-catalyzed allylation of aldehydes in acetonitrile, (a) As-pinall, H.C. Greeves, N. Mclver, E. G. Tetrahedron Lett. 1998, 39, 9283. For acetic acid acceleration in Yb(fod)3-catalyzed ene reaction of aldehydes with alkyl vinyl ethers, ene reaction of aldehydes with alkyl vinyl ethers, (b) Deaton, M. V. Ciufolini, M.A. Tetrahedron Lett. 1993, 34, 2409. Yamamoto et al. reported Brpnsted acid-assisted chiral Lewis acids and Lewis acid-assisted Brpnsted acids which were used for catalytic asymmetric Diels-Alder reactions and protonations and stoichiometric asymmetric aza Diels-Alder reactions, aldol-type reactions of imines, and an aldol reaction, (c) Ishihara, K. Yamamoto, H. J. Am. Chem. Soc. 1994, 116, 1561. (d) Ishihara, K. Kurihara, H. Yamamoto, H. J. Am. Chem. Soc. 1996, 118, 3049. (e) Ishihara, K. Nakamura, S. Kaneeda, M. Yamamoto, H. J. Am. Chem. Soc. 1996, 118, 12854. (f) Ishihara, K. Miyata, M. Hattori, K. Tada, T. Yamamoto, H. J. Am. Chem. Sc c. 1994, 116, 10520. (g) Yamamoto, H. J. Am. Chem. Soc 1994, 116, 10520. (h) ishihara, K. Kurihara, H. Matsumoto, M. Yamamoto Ishihara, K. Kurihara, H. Matsumoto, M. Yamamoto, H. J. Am. Chem. Soc 1998, 120, 6920. 

X. fran.v-Pd(NH3)2Cl2/f-BuOH isomerizes allyl ethers to vinyl ethers that can then be hydrolyzed in 90% yield, but in the presence of an a-hydroxy group the intermediate vinyl ether cyclizes to an acetal. This reagent does not affect benzylidene acetals. 

Both IH- and 4//-chromenes are accessible from 2-allyIphenols. Isomerisation to the internal alkene and O-allylation followed by RCM using a Grubbs second generation catalyst affords the former benzopyrans. Conversion of the allylphenol to the vinyl ether prior to RCM gives the 4/f-[l]benzopyrans <05T9996>. 

The preceding study has demonstrated [2.2.1]bicycloheptenyl functionalized resins can be useful and interesting ene components in photoinitiated thiolene polymerizations. The addition of thiols to the unsaturation of this bicyclic system appears to be rapid and exothermic. The relative rates of this addition compared with allylic derivatives and vinyl ethers are quite favorable. The organic resins can be readily prepared from either polyols, f>olyamines, or acrylic precursors (Figure 10) and the yields are generally quite good. When acrylate esters are used as precursors, the cycloaddition reaction occurs spontaneously and no catalysis of the reaction is necessary. 

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