Vinylene carbonate

The NMR spectrum of the 2-hydroxy-1,3-dioxolylium cation (117) (68JA1884) shows a significant ring current. The aromaticity of vinylene carbonate was pointed out by Balaban (59MI40100). 

Other routes to oxocarbenes are the a-elimination of bromine from a,a-dibromo ketones (73JA2708, 73JA5416), and the elimination of CO2 or COS from dioxolenones (vinylene carbonates) or their sulfur analogues. The former reaction has not been investigated with regard to oxirene involvement the latter is discussed in Section 5.05.6.3.5. The formation of an oxocarbene from a chlorooxirane was mentioned in Section 5.05.6.3.2. 

Of much greater promise than thermolysis for the detection of oxirene is low-temperature photolysis. Strausz and coworkers (80JOC2271) investigated the photolysis, in an argon matrix at low temperatures, of 1,3-dioxolenone (vinylene carbonate 125). However, the only C2H2O species detected was ketene. The sulfur derivatives of (125), compounds (126) and... 

Enandoselecdve total synthesis of andhingal agent Sch-38516 is reported. Stereocontrolled carbohydrate synthesis is based on the 1,3-dipolar cycloaddidon of chiral nkrone to vinylene carbonate, as shovm in Eq. 8.53. ... 

Numerous research activities have focused on the improvement of the protective films and the suppression of solvent cointercalation. Beside ethylene carbonate, significant improvements have been achieved with other film-forming electrolyte components such as C02 [156, 169-177], N20 [170, 177], S02 [155, 169, 177-179], S/ [170, 177, 180, 181], ethyl propyl carbonate [182], ethyl methyl carbonate [183, 184], and other asymmetric alkyl methyl carbonates [185], vinylpropylene carbonate [186], ethylene sulfite [187], S,S-dialkyl dithiocarbonates [188], vinylene carbonate [189], and chloroethylene carbonate [190-194] (which evolves C02 during reduction [195]). In many cases the suppression of solvent co-intercalation is due to the fact that the electrolyte components form effective SEI films already at potential which are positive relative to the potentials of solvent co-intercalation. An excess of DMC or DEC in the electrolyte inhibits PC co-intercalation into graphite, too [183]. 

C21H26N2O5 2122-39-6) see Vincamine vinylene carbonate (C,H203 872-36-6) see Bisantrene vinyl-p-ionol... 

Vinyl acetate, 57,117 Vinylacetic acid, 56,49 ct-Vinylbenzyl alcohol, 56, 106 Vinyl bromide, 58,152, 155, 157 Vinyl chloride, 58,133 Vinylene carbonate, 57, 117 Vinylmagnesium halides, 59,92 2-Vinylpytidine, 58, 73 Vinyl sulfides, 59, 202... 

The isoquinolinium ylide 241 reacts with allyl alcohol in a [3+2] cycloaddition to give the tetracyclic product 242 (Equation 32) the primary cycloaddition product spontaneously undergoes an intramolecular transesterification to give the isolated furanone. Similarly, reaction of such ylides with vinylene carbonate gives the tetracycles 243 (Equation 33) <1988BCJ2513>. 

Cycloadducts have been successively obtained by reaction of MCP with maleic anhydride (116) and a number of related electron-deficient alkenes (137,486,487) under photolytic conditions in the presence of a sensitizer (Table 38, entries 5-8) [132b]. Analogous cycloadditions in mild conditions with high yields have also been performed with electron-donor substituted alkenes, such as vinylene carbonates 483 and 484 and the imidazolinone 485 (entries 2-4) [132], In the case of the unsymmetrical anhydride 137 (entry 6), an almost equimolar mixture of both the possible regioisomers has been obtained [132b]. In all these cases the reaction has also been proposed to occur via diradical intermediates formed from the reaction of 1 with the alkene in its excited triplet state [132]. 

Irradiation of the cycloalkenone (218) with vinylene carbonate in THF resulted in the separation of (219), which yielded the p,y-unsaturated aldehyde (220) upon treatment with KOH in MeOH at room temperature (Table 12) 73 . 

Ogasawara employed a Heck reaction of o-iodoaniline derivatives with dihydrodimethoxyfuran and vinylene carbonate to give intermediates that are readily cyclized to indoles with acid [381-383]. An example is shown below [381]. 

Oxygen. The very weak aromaticity in vinylene carbonate (92) and o-phenylene carbonate is enhanced by protonation to 93 and 97, respectively, as evidenced by electronic spectra of 94135 and lH NMR spectra of 93136 (Scheme 44). 

The lithium-storage properties of these Si SiOx/C nanocomposite electrodes were investigated in different electrolyte systems and compared to pure Si nanoparticles. From all the analyzed systems, the Si SiOx-C nanocomposite in conjunction with the solvent vinylene carbonate (VC) to form the solid-electrolyte interface showed the best lithium storage performance in terms of a highly reversible lithium-storage capacity (1100 mAh g-1), excellent cycling performance, and high rate capability (Fig. 7.9). 

Among the various additives tested, vinylene carbonate (VC) might be the most famous in the lithium ion research and development community, although the number of publications related to it seems to be rather small. Its importance can be evidenced by the number of companies that vied for the patent rights for... 

A very remote secondary H/D isotope effect has been measured for the 2 + 2-cycloaddition of TCNE to 2,7-dimethylocta-2,fran -4,6-triene. The reaction of nitric oxide with iV-benzylidene-4-methoxyaniline to produce 4-methoxybenzenediazonium nitrate and benzaldehyde is thought to proceed via a 2 + 2-cycloaddition between nitric oxide and the imine double bond. A novel mechanism for the stepwise dimerization of the parent silaethylene to 1,3-disilacyclobutane involves a low-barrier [1,2]-sigmatropic shift. Density functional, correlated ab initio calculations, and frontier MO analysis support a concerted 2 + 2-pathway for the addition of SO3 to alkenes. " The enone cycloaddition reactions of dienones and quinones have been reviewed. The 2 + 2-photocycloadditions of homochiral 2(5H)-furanones to vinylene carbonate are highly diastereoisomeric. ... 

Scheme 40 Synthesis of furanose-fused y-butyrolactones by photocycloaddition of vinylene carbonate to substituted butenolides...

Garner et al. (90,320) used aziridines substituted with Oppolzer s sultam as azomethine ylide precursors. The azomethine ylide generated from 206 added to various electron-dehcient alkenes, such as dimethyl maleate, A-phenylmalei-mide, and methyl acrylate, giving the 1,3-dipolar cycloaddition product in good yields and up to 82% de (for A-phenylmaleimide). They also used familiar azomethine ylides formed by imine tautomerization (320). Aziridines such as 207 have also been used as precursors for the chiral azomethine ylides, but in reactions with vinylene carbonates, relatively low de values were obtained (Scheme 12.59) (92). 

The homochiral 2(57/)-furanone 141 undergoes photochemical cycloaddition to vinylene carbonate <1996T1267, 1998TL6961> to generate cycloadducts derived from an r-vo-approach (Equation 45). 

The known adduct (385) of furan and vinylene carbonate, previously used for the synthesis of some cyclitols,256,257 has been transformed into DL-ribose derivatives. After hydroxylation of 385 and subsequent formation of the isopropylidene derivative, the carbonate group was removed by treatment with barium hydroxide, and the resulting diol was cleaved by oxidation with permanganate. Dicarboxyl-ic acid 386 gave, upon treatment with acetic anhydride, cyclic anhydride 387. The reaction of 387 with azidotrimethylsilane produced... 

Ethenediyl carbonate (l,3-dioxol-2-one vinylene carbonate, 417) is a readily available,270 versatile synthon having pronounced dienophilic properties.270-275 Diels-Alder adducts of 417 with 1,4-di-acetoxy-1,3-butadiene and furan were selectively converted into cy-clitols,256 257-275 and also served as precursors of DL-ribose derivatives258 (see Section IV, 2). Another possibility of applying 417 as an equivalent of a 1,2-dihydroxyethane unit has been demonstrated in a synthesis of racemic apiose. Photochemical cycloaddition of 417 to 1,3-diace-toxy-2-propanone (418) gave the oxetane derivative 419, which, on alkaline hydrolysis, afforded DL-apiose (420) in 23% yield.1... 

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