Acetylenedicarboxylic acid, dimethyl

Irradiation of 5-acetyldibenz[i>,/]azepine (19) in the presence of. V-methylmaleimide results in a mixture of the homo dimer 20 and the mixed dimer 21. No [2 + 2] cycloadducts are obtained, however, with other alkenes such as styrene, acetylenedicarboxylic acid, dimethyl fumarate or acrylonitrile.32 Later studies have demonstrated that the dimerization occurs via the excited triplet state.196... 

Acetylenedicarboxylic acid, dimethyl ester, 50, 25, 36 Acetylenes, reaction with tri-methylsilyl azide, 50, 109 Acetylenic sulfonium salts, furans from, 53, 3 2-Acetylindane-l,3-dione, 52, 4 2-ACETYL-6-METHOXYNAPHTHALENE, 53, 5... 

Dimethyl acetylenedicarboxyl ate Acetylenedicarboxylic acid, dimethyl ester (8) 2-Butynedioic acid, dimethyl ester (9) (762-42-5)... 

DIMETHYL ACETYLENEDICARBOXYLATE (Acetylenedicarboxylic acid, dimethyl ester)... 

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]. 

Propargyl bromide 1-Propyne, 3-bromo- (8,9) (106-96-7) Dimethyl acetylenedicarboxylate Acetylenedicarboxylic acid, dimethyl ester (8) 2-Butynedioic acid, dimethyl ester (9) (762-42-5) l,2-Hexadien-5-yne (8,9) (33142-15-3)... 

The hydrogenation of acetylenedicarboxylic acid dimethyl ester (80) and diphenylacetylene (83) with [RhH2(0C(==0)0H)(PPr 3)2] gives dimethyl fumarate (82) and fraws-stilbene (84), respectively. This complex also catalyzes an isomerization of ds-stilbene to fra s-stilbene, though hydrogenation of alkyne is about eight times faster than the isomerization. ... 

Acetylenedicarboxylic acid, dimethyl ESTER, 32, SS Acetylenic glycols, 39, 57 2- -Acetylphenylhydroquinone, 84,1 S-ACETYL-n-VALERIC ACID, 31, 3 Acid chlorides, 39, 19 synthesis of, 37, 69... 

The cationic complex (VII, X = Cl) forms a symmetrical ( Pnmr i.r.) complex with diphenylacetylene, which is very labile. The complexes [Rh2Cl2(/Lt-CO)(/Lc-acet)(dppm)2], where acet is hexafluoro-2-butyne or acetylenedicarboxylic acid dimethyl ester, are also symmetrical, and the acet ligand is coplanar with the rhodium atoms. The C C bond length is increased to 1.32 A, and so the complex is truly described as a cis-dimetallated alkene. Comparison with the reactions with CO suggests that the activation of an alkyne (or alkene) to hydrogenation may occur when the alkyne is initially coordinated to the catalyst at a terminal position, e.g., (XII), with subsequent oxidative addition and hydrogen transfer steps. A complex of the type (XII) may instead be only a minor but active component of a solution of which the alkyne-bridged complex is the major but less active component. ... 

As is true for hydrostannation, acetylenes are also more reactive than the olefins toward hydroplumbation. Acetylenedicarboxylic acid dimethyl ester and ethyl propiolate 152) add Bu3PbH at — 50° C (used as a pure substance, or made in situ from organotin hydrides) spontaneously and without side reactions. Me3PbH adds in the same smooth manner to cyanoacetylene and methyl propiolate 165). Phenylacetylene reacts under the same conditions but in a side reaction Pb is precipitated and H2 evolves. After a short while starting materials disappear if excess of lead hydride is used. The IR spectrum shows absorption at 990 cm , which is in accordance with a trans adduct 152,194). 

Kuz mina, N.Ya., M.L. Petrov, and A.A. Petrov. 1984. The effects of substituents in dithioate-anions on the course of the reaction with acetylenedicarboxylic acid dimethyl ester. Zh Org Khim 20 (12) 2511-2517. 

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