Acetylenedicarboxylic ester

An interesting rearrangement which is based on the intramolecular acylation of an enamine by an ester is found in the aromatization of the adduct derived from N-methylpyrrole and an acetylenedicarboxylic ester (407,408). 

Reaction of the mesoionic oxazolone 620 with acetylenedicarboxylic ester 621 gave the cycloadduct 622 in aprotic solvents and the Michael adducts... 

These reactions are found to be promoted by electron-donating substituents in the diene, and by electron-withdrawing substituents in the alkene, the dienophile. Reactions are normally poor with simple, unsubstituted alkenes thus butadiene (63) reacts with ethene only at 200° under pressure, and even then to the extent of but 18 %, compared with 100% yield with maleic anhydride (79) in benzene at 15°. Other common dienophiles include cyclohexadiene-l,4-dione (p-benzoquinone, 83), propenal (acrolein, 84), tetracyanoethene (85), benzyne (86, cf. p. 175), and also suitably substituted alkynes, e.g. diethyl butyne-l,4-dioate ( acetylenedicarboxylic ester , 87) ... 

After acetylenedicarboxylates, esters of propiolic acid are the second common group of reagents for 1,3-dipolar cycloaddition with azides. They react fast, and the yields of products are high. However, because the reacting... 

Dihydronaphthalen-1,4-iwmes from Isoindoles The naphthalen-l,4-imine derivatives 91-99 have been obtained by addition of acetylenedicarboxylic esters to the appropriate isoindoles. 3- ss Some such adducts react further with acetylenic esters (see Sections III, G and H), so that A -ethyl- and A-n-butylisoindole give 1 2 adducts with dimethyl aoetylenedicarboxylate instead. iV-Methylisoindole appears to be exceptional in giving an oily 2 1 adduct, for which structure (100) was suggested on analogy with the 2 1 adduct obtained from l,3-diphenylbenz[c]furan and acetylenedicarboxylic acid. ... 

Ring expansion of 4-pyrrolidinylcoumarin with acetylenedicarboxylic ester leads to benzoxocinone (154) in 43% yield (77JCS(P1)2457). 

The ultraviolet absorption spectra have been used to distinguish between the tautomers obtained by addition of dimethyl acetylene-dicarboxylate to pyridines. The 4/f-quinolizines show a band around 265 mfi. which is missing from the spectra of the 9a/f-quinolizines. Acheson and Taylor26 have successfully used this information to settle the constitution of the stable and labile adducts obtained by the action of acetylenedicarboxylic esters on pyridines. The ultraviolet spectra of the stable adducts formed by the above methods show... 

Such reactions occur readily with alkynic esters, but the products isolated are often complex. Thus, the initial Michael adduct of type (68) from pyridine with acetylenedicarboxylic ester reacts with more alkynic ester to yield (66), (67) and other products. Quinoline and isoquinoline react similarly. 

Pyrroles can be a-alkenylated by acetylenedicarboxylic ester, as discussed in Section 3.3.1.8.1. 

Indolizines can also be produced from pyridine and acetylenedicarboxylic ester (Section 3.2.1.3.7). 

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). 

Benzo[Z> jthiophene 1,1-dioxide cycloadds to acetylenedicarboxylic ester to yield naphthalene-1,2-dicarboxylic ester after extrusion of S02. However, maleic anhydride and benzoquinone are reported not to react with benzo[Z>]thiophene dioxide (70AHC(ll)l77). 

The Michael-type addition of morpholine to propiolic, tetrolic, phenylpropiolic, and acetylenedicarboxylic esters has been described by Postovskii et al.500... 

The reaction of 1,8-naphthylenediamine with acetylenedicarboxylic ester leads to the mixture of compounds 519-521. The major products of this reaction are compounds 520 and 521, whereas 1,4-diazepine derivatives 519 are formed in a yield of 1% only (86MII). Structure 522 proposed for one of the products is incorrect (NK2161,62NKZ597 83BCJ2338 86MI1). 

When the 5-amino- or 5-alkoxytriazoline contains an electron-withdrawing group in the 4-position with no free hydrogen, photolysis leads to unstable aminoaziridines, readily hydrolyzable in air, to give amides via azomethine ylides. In the presence of acetylenedicarboxylic ester, photolysis yields a pyrroline and a pyrrole (Scheme 158).250... 

Dipolar Cycloaddition of Azimine with Acetylenedicarboxylic Esters... 

The three-nitrogen azimine 1,3-dipolar system in benzocinnolinium ylides26 undergoes cycloaddition with acetylenedicarboxylic esters to give azomethineimines, presumably derived from the initial A4-triazoline 1,3-cycloadduct by an electrocyclic ring opening (Scheme 8).2 7... 

Pyrroles can be -alkenylated by reaction with acetylenedicarboxylic ester, for example, to give an /Z mixture (1 3.3) of alkenes 110 (Scheme 48) <2006JOC7793>. 

Aryl-4-nitrosydnones react with acetylenedicarboxylic esters with the formation of l-aryl-3-nitro-4,5-pyrazoledicarboxylate [556] (Scheme 100). 

Three reactions, which were known from the literature to be catalyzed by Lewis acids were selected as test reactions. A, was the Reetz alkylation of silyl enol ethers with -butyl chloride for which titanium tetrachloride is known to be useful [52]. B, was the Diels-Alder reaction between furan and acetylenedicarboxylic ester for which aluminium trichloride is a good catalyst [53]. C, was a Friedel-Crafts acylation for which aluminium trichloride is the preferred catalyst [54]. The reactions are summarized in Scheme 6. 

Dimethirimol, structure, 55, 134 Dimethyl acetylenedicarboxylate, see Acetylenedicarboxylic ester... 

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