Acetylenedicarboxylic add

Dimethyl acetylenedicarboxylate adds to 98 574 and 99 575 to give the 1 1-molar adducts 100 and 101, the original ring being opened, and-similar reactions have been observed with 102578 and 103.875... 

Diels-Alder Reaction. By means of the Diels-Alder reaction a considerable number of hydrobiphenyls have been prepared, from which it should be possible to obtain unsymmetrical biaryls by dehydrogenation. Only a few of the adducts have been converted to the completely aromatic compounds. o-Terphenyl has been prepared from the adduct of maleic anhydride and 3,4-diphenylcyclopentadienone, and p-terphenyl has been obtained in practically quantitative yield from the adduct of the methyl ester of acetylenedicarboxylic add and 1,4-diphenylbutadiene. ... 

Azavinylogous amidinium salts (188 equation 103) were obtained by treatment of triazenes with methyl iodide. 47 Acetylenedicarboxylic add ester reacts with the diazonium salt (189 equation 104) via cycloaddition to give the imidazolium salt (190). 4S... 

Acetylenedicarboxylic add, HOjCC CCOzH, m.p, 175°. Suppliers Farchan, A, B, F. Preparation by reaction of a, 8-dibromosuccinic acid with methanolic potassium hydroxide, isolation of the potassium acid salt, acidification, and extraction with ether. The potassium acid salt is available from National Aniline and from Eastman. 

Acetic add, frons-cyclohexanediaminetetra-metal complexes, 554 Acetic add, ethylenediaminetetra-in analysis, 522 masking, 558 metal complexes, 554 Acetic acid, iminodi-metal complexes, 554 Acetic acid, nitrilotri-metal complexes titrimetry, 554 Acetoacetic add ethyl ester bromination, 419 Acetone, acetyl-deprotonation metal complexes, 419 metal complexes reactions, 422 Acetone, selenoyl-liquid-liquid extraction, 544 Acetone, thenoyltrifluoro-liquid-liquid extraction, 544 Acetone, trifluorothenoyl-in analysis, 523 Acetonitrile electrochemistry in, 493 exchange reactions, 286 metal complexes hydrolysis, 428 Acetylacetone complexes, 22 liquid-liquid extraction, 543 Acetylacetone, hexafiuorothio-metal complexes gas chromatography, 560 Acetylactone, trifluorothio-metal complexes gas chromatography, 560 Acetylation metal complexes, 421 Acetylenedicarboxylic add dimethyl ester cycloaddition reactions, 458 Acid alizarin black SN metallochromic indicator, 556 Actinoids... 

The mesoionic 3-oxido-N-alkylpyridinium betaine 15-whose electronic description formally corresponds to that of 1,3-dipoles a/b - undergoes cycloadditions with activated alkynes and aUcenes. Thus, phenylacetylene (and analogously acrylate) adds via C-2/C-6 to give 8-azabicyclo[3.2.1]octane derivatives 16. In contrast, dimethyl acetylenedicarboxylate adds via O/C-2 to give as primary product the furo-l,2-dihydropyridine 17, which subsequently is converted to the furan derivative 18 by 67t-electrocyclic N/C-2 opening of the dihydropyridine ring [146] ... 

Photolysis of S2C12 in alkane solvents gives alkyl chlorides, di- and poly-sulphides, HCl, and sulphur. Di-2-indolyl disulphides are formed by treating 3-substituted indoles with S2CI2, minor products being mono- and tri-sulphides. Diethyl acetylenedicarboxylate adds to S2CI2 to give the bis-(2-chlorovinyl) disulphide. ... 

Dicyanoacetylene, 2-hiitynedinitri1e, is obtained from dimethyl acetylenedicarboxylate by ammonolysis to the diamide, which is dehydrated with phosphoms pentoxide (44). It bums in oxygen to give a flame with a temperature of 5260 K, the hottest flame temperature known (45). Alcohols and amines add readily to its acetylenic bond (46). It is a powerhil dienophile in the Diels-Alder reaction it adds to many dienes at room temperature, and at 180°C actually adds 1,4- to benzene to give the bicyclo adduct (7) [18341 -68-9] C QHgN2 (47). 

Few isothiazoles undergo simple cycloaddition reactions. 4-Nitroisothiazoles add to alkynes (see Section 4.17.7.4). With 5-thiones (84) and dimethyl acetylenedicarboxylate, addition to both sulfur atoms leads to 1,3-dithioles (85) (77SST(4)339, 80H(14)785, 81H(16)156, 81H(16)595). Isothiazol-3-one 1-oxide and the corresponding 1,1-dioxide give normal adducts with cyclopentadiene and anthracene (80MI41700), and saccharin forms simple 1 1 or 1 2 adducts with dimethyl acetylenedicarboxylate (72IJC(B)881). 

Pyridine and dimethyl acetylenedicarboxylate in methanol yield - a mixture of (33) and (34). It is tempting to assume that a zwitterion (30) is first formed and that this then adds a proton followed by a methoxide ion (Michael addition) under the influence of both the positive charge on the ring and the assisting ester group. The resulting structure (31) could then add another molecule of the ester and cyclize, as indicated, to (32). Subsequent aromatization accompanied by loss of one, or the other, substituent at position 3 would lead to the two products, (33) and (34), actually isolated. 

A number of other ligand groups are found to add to [Ni(CNBu )2] t, including azobenzene, tetracyanoethylene, fumaronitrile, and maleonitrile, diphenylacetylene and dimethyl acetylenedicarboxylate 109,110) [Eq. (29)]. 

In a manner similar to OsH(OH)(CO)(P Pr3)2, the hydride-metallothiol complex OsH(SH)(CO)(P Pr3)2 adds Lewis bases that are not bulky such as CO and P(OMe)3 to give the corresponding six-coordinate hydride-metallothiol derivatives OsH(SH)(CO)L(P Pr3)2 (L = CO, P(OMe)3). OsH(OH)(CO)(PiPr3)2 and OsH(SH)(CO)(P Pr3 also show a similar behavior toward dimethyl acetylenedi-carboxylate. Treatment of OsH(SH)(CO)(P Pr3)2 with this alkyne affords 6sH SC(C02Me)CHC(OMe)6 (CO)P Pr3)2, which is the result of the tram addition of the S—H bond to the carbon-carbon triple bond of the alkyne. Phenyl-acetylene, in contrast to dimethyl acetylenedicarboxylate, reacts with OsH(SH) (CO)(P Pr3)2 by insertion of the carbon-carbon triple bond into the Os—H bond to give the unsaturated alkenyl-metallothiol derivative Os ( )-CH=CHPh (SH) (CO)(P Pr3 )2, the inorganic counterpart of the organic a, (3-unsaturated mercaptans (Scheme 46).92... 

Diphenyl ditelluride adds to alkynes upon irradiation with a tungsten lamp in the absence of solvent to give 1,2-bis(phenyltelluro)alkenes (Equation (67)).191 The ( )-isomers are obtained as the major product through a radical chain mechanism. Functionalized internal alkynes such as dimethyl acetylenedicarboxylate and dihaloalkynes XCCX (X = C1 or Br) are able to participate in the reaction.192... 

This route relies on 1,3-dipolar cycloaddition reactions a series of dihydropyrrolizines 213 were synthesized by heating the proline derivatives 211 with dimethyl acetylenedicarboxylate (DMAD) at 130-140 °C in the presence of acetic anhydride. Reaction between 211 and AczO provides the mesoionic oxazalone intermediate 212 which adds to dimethyl acetylenedicarboxylate, giving a cycloadduct, which undergoes spontaneous decarboxylation leading to 213 (Scheme 50) <1998JME4744, 1977JME812>. 

Details have appeared39 of the addition of PH-tetraoxyspirophosphoranes to aldehydes and activated ketones. These phosphoranes also add to activated acetylenes,40 e.g. diethyl acetylenedicarboxylate with (50) gives a mixture of cis- and trans-(51). Further addition of (50) to (51) at higher temperatures gives the bisphos-phorane (52). Metallation of the spirophosphorane (53) followed by reaction with... 

Hydrazoic acid adds readily to acetylenes with electron-withdrawing groups, and less readily to alkyl and aryl acetylenes.Acetylene itself gives a high yield of i -triazole under carefully controlled conditions. Not all acetylenes give triazoles with hydrazoic acid. Open-chain azides have been obtained with ethoxyacetylene and with dimethyl acetylenedicarboxylate... 

Norbornadiene adds typical dienophiles in a homo-Diels-Alder reaction whereby, for example, the adduct 86 is obtained with tetra-cyanoethylene. Dimethyl acetylenedicarboxylate and dicyanoacetyl-ene add to barrelene (bicyclo[2.2.2]octa-2,5,7-triene) in a similar way. °... 

The meso-ionic l,3-dithiol-4-ones (134) participate - in 1,3-dipolar cycloaddition reactions giving adducts of the general type 136. They show a remarkable degree of reactivity toward simple alkenes including tetramethylethylene, cyclopentene, norbomene, and norbor-nadiene as well as toward the more reactive 1,3-dipolarophilic olefins dimethyl maleate, dimethyl fumarate, methyl cinnamate, diben-zoylethylene, A -phenylmaleimide, and acenaphthylene. Alkynes such as dimethyl acetylenedicarboxylate also add to meso-ionic 1,3-dithiol-4-ones (134), but the intermediate cycloadducts are not isolable they eliminate carbonyl sulfide and yield thiophenes (137) directly. - ... 

Diels-Alder reactions of thiophene 1,1-dioxides are very common (B-67MI31401). With rare exceptions, the adduct loses a molecule of SO2 to form a diene which may add another molecule of the dienophile. The sequence with maleic anhydride is shown in Scheme 193. It has been claimed that in the reaction of thiophene dioxide with acetylenedicarboxylic ester the primary adduct could be isolated, but this could not be substantiated (75RTC85). 

Although chromenes are not sufficiently reactive, 2/f-naphtho[ 1,2-6]pyrans (202) add reactive dienophiles such as dimethyl acetylenedicarboxylate in a Diels-Alder reaction. 

Moore et a/.462 have studied cycloadditions to the 1,2-diazepinium betaines (1), which are also vinylogous azomethine imines. Ketenes and isocyanates add in a 1,5 manner and rearrange to 1,3-cycloadducts. Dimethyl acetylenedicarboxylate gave in 30 minutes 33% of 2, the formal product of a 1,3-cycloaddition, but possibly formed via a 1,5-cycloaddition. On heating, 2 gave 6 and another product via the postulated intermediates 4 and 7. Thermolysis of the related compounds 3 463 gave 5.464... 

A number of examples of photoaddition to alkynes has been described. Dimethyl acetylenedicarboxylate has been found to add to methyl-substituted 3-benzoylthiophens301 and to thiophen and 2,5-dimethylthiophen302 on irradiation. Benzo[f>]thiophen also undergoes cycloaddition reactions with alkynes,303 and in the case of dimethylacetylene dicarboxylate, product formation has been shown to be wavelength dependent.304 Intramolecular [ 2 -(- 2] cycloaddition has been observed on both direct and triplet-sensitized irradiation of the alkyne (353) and gives the cyclobutene (354)305 the isomer (355) is formed on prolonged irradiation. 

Addition to dimethyl acetylenedicarboxylate.22 The copper reagent prepared by reaction of RMgBr and CuBr S(CH3)2 in THF adds stereoselectively to dimethyl acetylenedicarboxylate to give dimethyl 2-alkylmaleates in 70-95% yield (equation I). 

Bryce-Smith and Lodge [3] have discovered that methyl propiolate, dimethyl acetylenedicarboxylate, and phenylacetylene add to benzene upon irradiation at 50°C. The products are cyclooctatetraenes, formed via initial ortho addition of the acetylene to benzene followed by ring opening (Scheme 9). 

Having sufficient amounts of these novel dienes in hand opens the field for further study. Cycloaddition of acetylenedicarboxylic acid dimethyl ester (ADDE) to [3]dendralene 7 in toluene first afforded the l l-adduct 43, which by a second addition of ADDE provided the expected 2 l-adduct 44. After this had been aromatized by treatment with DDQ to the naphthalene derivative 45, a double benzannulation could be carried out as described in Scheme 8 [13]. 

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