Diethyl Acetylenedicarboxylate Research Articles

1-Alkyl-1,2,4-triazinium Ylides as 1,3-Dipoles in a Cycloaddition Reaction with Diethyl Acetylenedicarboxylate

Deprotonation of 1-alkyl-5-phenyl-1,2,4-triazinium salts by triethylamine results in the formation of azomethyne ylides which undergo a 1,3-dipolar cycloaddition reaction with diethyl acetylenedicarboxylate to yield pyrrolo[2,1-f]1,2,4-triazines

A Convenient Synthesis of 2′,3′′′′-Dimethyl-p-sexiphenyl

Hitherto unreported 2′,3′′′′-dimethyl-p-sexiphenyl (6) is synthesized by an unambiguous route in good yield, starting from inexpensive commercially available biphenyl. The general reaction sequence consists of: (i) bischloromethylation of biphenyl, to give 4,4′-bis(chloromethyl)biphenyl (1) (ii) conversion of 1, to its bisphosphonium salt 2 (iii) a Wittig reaction of the salt with two equivalents of β-methylcinnamaldehyde to yield hitherto unreported 4,4′-bis(3-methyl-4-phenyl-buta-1,3-dienyl)biphenyl (3) (iv) the [4 + 2] cycloaddition of 3 with diethyl acetylenedicarboxylate to yield 4 (v) hydrolysis of 4 to 5 (vi) and oxidative decarboxylation of 5 with potassium hexacyano ferrate(III). All reactions which are simple and straightforward proceed in good yield, except the last step.

Synthesis of Some New 2(1H)-Pyridones from 3-Amino-3-(dialkylamino)propenenitriles

3-Amino-3-(dialkylamino)propenenitriles were reacted with acetylenecarboxylates to give 2(1H)-pyridone derivatives. The reaction with ethyl propynate afforded dienamino ester intermediates which cyclized in sodium ethoxide/ethanol to 5-cyano-2(1H)-pyridone. The reaction with diethyl acetylenedicarboxylate gave directly the 2(1H)-pyridone derivatives.

Electrochemistry of CU(I) Bipyridyl Complexes with Alkene, Alkyne, and Nitrile Ligands. Implications for Plant Hormone Action of Ethylene

The redox behavior was evaluated for several (BIPY)Cu(I) complexes (BIPY = 2,2'-bipyridyl) with unsaturated ligands by means of cyclic voltammetry in CH2Cl2 at reduced temperatures (-78 degrees, -23 degrees, 0 degree C). The complexes studied are [Cu(I)(BIPY)(C2H4)]PF6, [Cu(I)(BIPY)(3-hexyne)] PF6, [Cu(I)(BIPY)(DEAD)]PF6, ([Cu(I)(BIPY)]2 DEAD)[PF6]2 (DEAD = diethyl acetylene dicarboxylate) and [Cu(I)(BIPY)(CH3CN)]PF6. The oxidations are quasi-reversible at -78 degrees C for scan rates of 20 to 200 mV/sec. The reductions were irreversible on the CV time scale. Evidence is presented in support of a role for an electron transfer mechanism in the case of the plant hormone ethylene. Related literature data are also discussed.

Formation of novel 1 : 2 adducts between Bun3P·CS2and electron-deficient alkynes

The zwitterionic adduct between tri-n-butylphosphine and carbon disulphide reacts under neutral conditions with two equivalents of dimethyl and diethyl acetylenedicarboxylate, dibenzoylacetylene and methyl benzoylpropiolate to give novel crystalline dithiole-containing ylides whose structure is established by X-ray crystallography.

ChemInform Abstract: Synthesis of Pyridazino(3,4‐b)quinoxalines and Pyrazolo(3,4‐b)quinoxaline by 1,3‐Dipolar Cycloaddition Reaction.

The pyridazino[3,4-b]quinoxalines 6a,b and pyrazolo[3,4-b]quinoxaline hydrochloride 9 were synthesized by the 1,3-dipolar cycloaddition reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 5 with dimethyl or diethyl acetylenedicarboxylate and 2-chloroacrylonitrile, respectively. The reaction mechanisms were postulated for the formation of 6a,b and 9.

Synthesis of pyridazino[3,4‐b]quinoxalines and pyrazolo[3,4‐b]‐quinoxaline by 1,3‐dipolar cycloaddition reaction

AbstractThe pyridazino[3,4‐b]quinoxalines 6a,b and pyrazolo[3,4‐b]quinoxaline hydrochloride 9 were synthesized by the 1,3‐dipolar cycloaddition reaction of 6‐chloro‐2‐(1‐methylhydrazino)quinoxaline 4‐oxide 5 with dimethyl or diethyl acetylenedicarboxylate and 2‐chloroacrylonitrile, respectively. The reaction mechanisms were postulated for the formation of 6a,b and 9.

ChemInform Abstract: The Hurtley Reaction. Part 2. Novel Complexes of Disubstituted Acetylenes with Copper(I) Benzoates Having a Reactive Ortho C‐Cl or C‐Br Bond. X‐Ray Structural Characterization of Tetrakis(2‐chlorobenzoato)bis(diethyl acetylenedicarboxylate)tetracopper(I).

AbstractTetrameric Cu(I) benzoate (Ia) and the o‐halogen‐substituted Cu(I) benzoates (Ib) and (Ic), the postulated intermediates in the Hurley reaction, react with the activated acetylenedicarboxylates (II) to yield the stable, tetranuclear complexes (III).

ChemInform Abstract: Generation of β‐Carboline Azomethine Ylides Via Trimethylsilylmethyl Trifluoromethanesulfonate Quaternizations: Entry into the New Class of 11H‐Indolizino(8,7‐b)indole Heterocycles.

AbstractThe fused N‐(silylmethyl)pyridinium salts (III) or (VII), prepared from the β‐carbolines (I) or (VI) and trimethylsilylmethyl triflate (II), react with the activated olefins (IV) or diethyl acetylenedicarboxylate (VIII) to form the cycloadducts (Va) ‐ (Vc) or (IX) ‐ (XI).

The Hurtley reaction. 2. Novel complexes of disubstituted acetylenes with copper(I) benzoates having a reactive ortho carbon-chlorine or carbon-bromine bond. X-ray structural characterization of tetrakis(2-chlorobenzoato)bis(diethyl acetylenedicarboxylate)tetracopper(I)

The Hurtley reaction. 2. Novel complexes of disubstituted acetylenes with copper(I) benzoates having a reactive ortho carbon-chlorine or carbon-bromine bond. X-ray structural characterization of tetrakis(2-chlorobenzoato)bis(diethyl acetylenedicarboxylate)tetracopper(I)

New Intermediates in the Cyclocotrimerization of Thioxophosphorus(V) Cations with Alkynes

A thiaphosphametallacyclopropane and a thiaphosphametallacycloheptadiene are important intermediates for understanding the mechanism of the cyclotrimerization of thioxophosphorus(V) cations and alkynes. These species are accessible by use of a bulky substituent R at the phosphorus atom. Compounds 2 are formed from the metallacyclopropane 1 and dimethyl or diethyl acetylenedicarboxylate in hexane. Upon heating in THF, they lose CO and are transformed into the known metallabicycloheptadienes 3. R1 = cyclohexyl; R2 = CO2Me, CO2Et.

Generation of β-carboline azomethine ylides via trimethylsilylmethyl trifluoromethane sulfonate quaternisations: Entry into the new class of 11H-indolizino[8,7-b]indole heterocycles

Norharman ( 1a ), ethyl N-tosyl-β-carboline-3-carboxylate ( 1b ) and N-benzyl-3,4-dihydronorharman ( 4 ) were quaternised with trimethylsilylmethyl trifluoromethane sulfonate and the corresponding azomethine ylides were generated with caesium fluoride; 1,3-dipolar cycloaddition of these ylides with diethyl acetylene dicarboxylate yielded the first known examples of 11 H-indolizino[8,7- b]indoles.

ChemInform Abstract: 1,3‐Dipolar Cycloadditions to Oxidopyraziniums.

Abstract 1,5-Dimethyl-3-oxidopyrazinium (6) undergoes cycloadditions with methyl acrylate, acrylonitrile, diethyl maleate, maleimide, methyl propiolate and diethyl acetylenedicarboxylate.

The Reactions of Tropone Tosylhydrazone Sodium Salt with Acetylene Derivatives Possessing Electron-Withdrawing Groups: A Novel Method of Synthesis of 1H-1,2-Benzodiazepine Derivatives

Abstract Reactions of tropone tosylhydrazone sodium salt with dimethyl and diethyl acetylenedicarboxylate gave dimethyl and diethyl 1H-1,2-benzodiazepin-3,4-dicarboxylate, respectively. The same reactions, but using ethyl acetylenecarboxylate and 3-butyn-2-one, afforded ethyl 1H-1,2-benzodiazepin-4-carboxylate and 4-acetyl-1H-1,2-benzodiazepine, respectively, accompanied by 8-azaheptafulvene derivatives derived from the sodium salt and the acetylene derivatives, and p-toluenesulfinic esters formed from p-toluenesulfinic acid and the acetylene derivatives. Reactions of the sodium salt with ethyl 2-butynoate gave the corresponding sulfinic ester but afforded no diazepine derivative.

ChemInform Abstract: Photocycloaddition of Diethyl Acetylenedicarboxylate to 2‐Phenyl‐4H‐ 1,3‐benzothiazine Derivatives.

AbstractThe dimethoxyphenylbenzothiazine (I) and diethyl acetylenedicarboxylate (II) are photolyzed, yielding a mixture of benzonitrile (III) and the benzothiophene derivative (IV).

ChemInform Abstract: An Improved Preparation of Diethyl Chlorofumarate.

AbstractThe regioselective hydrochlorination of diethyl acetylenedicarboxylate (I), yielding diethyl chlorofumarate (II), is described.

NAD(P)+–NAD(P)H Model. 62. The Mechanism of the Silica Gel-Catalyzed Reduction with an NAD(P)H Model

Abstract The reduction of diethyl acetylenedicarboxylate, diethyl fumarate, and diethyl maleate as well as several α,β-unsaturated carbonyl compounds by a model of NAD(P)H on silica gel was examined. The order of the reactivity for the reduction was reverse to that of the degree of adsorption of the substrates onto the surface of silica gel. Semiquantitative analysis of the results suggests the possibility that silanol groups on the surface of silica gel act as general acid catalysts in the course of the reduction.

Preparation and characterization of some mixed ligand complexes of platinum(II)

The mixed ligand complexes PtX 2(ER 3)L and PtXY(ER 3)L (where ER 3 = PR 3 or AsMe 3; L = phosphine, arsine; X = Cl; Y = Cl, H or Me) have been prepared and characterized. Reaction of PtMe 2(ER 3)L with HCl yields PtMeCl(ER 3)L, in exclusively one of three possible isomeric forms. Excess tetramethyltin reacts with Pt 2Cl 2(μ-Cl) 2(PMe 2Ph) 2 giving both cis and trans Pt 2(μ-Cl) 2(PMe 2Ph) 2, as identified from the NMR spectra. Cleavage of Pt 2(μ-Cl) 2Me 2(PMe 2Ph) 2 with donor ligands such as AsPh 3, PMe 2 or pyridine, was useful as a synthetic route to the unsymmetrical methylchloro Pt II derivatives. The reaction of cis-[PtMe 2(PPh 3)(AsPh 3)] with excess dimethylacetylenedicarboxylate (DMA) yielded only one product, which was of the formula trans-[Pt{C(COOCH 3)C(COOCH 3)CH 3} 2(PPh 3)(AsPh 3)], with the alkenyl groups having the same geometry about the CC bond. The use of diethylacetylene-dicarboxylate (DEA) rather than DMA gave a similar product. However, when cis-[PtMe 2(PEt 3)(AsPh 3)] was allowed to react with DMA, two products of the formula trans-[Pt{C(COOCH 3)C(COOCH 3)CH 3} 2(PEt 3)(AsPh 3)] were obtained, with the stereochemistry of both alkenyl groups being either cis or trans.

1,3-dipolar cycloadditions to oxidopyraziniums

1,5-Dimethyl-3-oxidopyrazinium (6) undergoes cycloadditions with methyl acrylate, acrylonitrile, diethyl maleate, maleimide, methyl propiolate and diethyl acetylenedicarboxylate.

ChemInform Abstract: Novel Addition Reactions of New Cyclic Sulphur Ylides, 9‐Alkyl‐10‐cyano‐9‐thiaphenanthrenes with Acetylenic Electrophiles.

AbstractDie aus den Acetylendicarbonsäurediestern (IIa) und (IIb) mit (Ia) erhaltenen Spiroverbindungen (III) lagern sich thermisch in die 9‐Ringe (IV) um.