Synthesis of 2-(buta-1,3-diynyl)-N,N-dimethylanilines Using Reductive Methylation Step

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Basic hydrolysis of l,4-bis(triphenylphosphonio)buta-1,3-diene dihalides

Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1, 3-diene dichloride with 10% NaOH gave isomeric 4-diphenylphosphoryl-4-phenylbut-1(2)-enes and 1-diphenylphosphoryl-1-phe-nylbuta-1, 3-diene, the products of anionotropic migration of a phenyl group from the P atom to the α-position. Hydrolysis with Na₂CO₃ afforded only the diene product. In both cases, triphe-nylphosphine and triphenylphosphine oxide were isolated as secondary products. Dehydro-chlorination of 2-chloro-1,4-bis(triphenylphosphonio)but-2-ene dibromide with triphenylphosphine was proposed as a new convenient route to 1,4-bis(triphenylphosphonio)buta-1,3-diene dibromide.     

A novel cyclization reaction between 2,3-bis(trimethylsilyl)buta-1,3-diene and acyl chlorides with straightforward formation of polysubstituted furans

A novel cyclization process of 2,3-bis(trimethylsilyl)buta-1,3-diene with various acyl chlorides in the presence of aluminium trichloride affords 2,5-disubstituted or 2,3,5-trisubstituted furans in short reaction time; a subsequent acylation process of the furan ring occurs if the reaction time is prolonged.     

New approach to the synthesis of tetrazole-containing buta-1,3-diynes: The total synthesis of 1,4-bis(2-(tert-butyl)-2H-tetrazol-5-yl)buta-1,3-diyne

An approach for the total synthesis of 1,4-bis(2-(tert-butyl)-2H-tetrazol-5-yl)buta-1,3-diyne was reported. Developed approach to the synthesis of 1,4-bis(2-(tert-butyl)-2H-tetrazol-5-yl)buta-1,3-diyne can be used for obtaining different 2,5-bis(tetrazol-5-yl)-disubstituted five-membered heterocycles (e.g. thiophenes, pyrroles, furans etc.), as well as tetrazole-containing monomers for the synthesis of new types of electroconductive and high energetic polymers.     

Palladium(0)-catalyzed decarboxylation of buta-2,3-dienyl 2'-alkynoates: approach to the synthesis of 2-alkynyl buta-1,3-dienes

The Pd(PPh3)4-catalyzed decarboxylation of buta-2,3-dienyl 2'-alkynoates allows the rapid construction of 2-alkynyl buta-1,3-dienes. The carbon-carbon bond-forming reaction occurs at the central position of an allene moiety.     

Thermal oligomerization of methyl 4-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)buta-2,3-dienoate

Dimeric compounds formed as a result of thermal oligomerization of methyl 4-(1,3-dioxo-2,3- dihydro-1H-isoindol-2-yl)buta-2,3-dienoate were identified.     

Synthesis and Structure of 2,3-Bis(5-tert-butyl-2-methoxyphenyl)buta-1,3-diene by Bromine Elimination of (Z)-1,4-Dibromo-2,3-bis(5-tert-butyl-2-methoxyphenyl)-2-butene

2,3-Bis(5-tert-butyl-2-methoxyphenyl)buta-1,3-diene was prepared by bromination of (Z)- and (E)-2,3-bis(5-tert-butyl-2-methoxyphenyl)-2-butene followed by treatment with zinc powder in a mixture of CH₂Cl₂ and acetic acid, which was converted to the corresponding o-terphenyl skeleton by the condensation with dimethyl acetylenedicarboxylate followed by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone.     

Studies on cyclization of o-(alka-1,3-diynyl)arenediazonium salts

The Richter reaction of o-(alka-1,3-diynyl)arenediazonium salts, obtained by diazotization of diacetylenic derivatives of anilines, leads to 3-alkynyl-4-chloro- or 3-alkynyl-4-bromocinnolines and/or 3-alkynyl-4-hydroxycinnolines (the latter cyclize into furo[3,2-c]-cinnolines under the reaction conditions). 3-Alkynyl-4-chlorocinnolines undergo solvolysis in methanol giving rise to 3-alkynyl-4-methoxycinnolines, the subsequent hydrolysis of which also gives furo[3,2-c]cinnolines. Effects of the nature of substituents in the aromatic ring and of the reaction conditions on the product composition and yields have been established. The reaction course has been studied by spectrophotometry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1693–1700, August, 2008.     

(Z,Z)-2,3-bis(trimethylsilyl)-1,4-dibromo- and 2,3-bis(trimethylsilyl)-1,1,4,4-tetrabromobuta-1,3-dienes. Synthesis and Diels-Alder reactions.

The two title compounds (1,2) have been prepared and some Diels-Alder reactions investigated.     

One-step synthesis of [4-(alkylsulfanyl)buta-1,3-diene-1-yl]-triphenylphosphonium iodides from buta-1,3-diene-1,4-diylbis(triphenylphosphonium) iodide

Buta-1,3-diene-1,4-diylbis(triphenylphosphonium) iodide reacted with alkanethiols at room temperature in the presence of triethylamine to give [4-(alkylsulfanyl)buta-1,3-diene-1-yl]triphenylphosphonium iodides and triphenylphosphine in high yields. Two presumable reaction mechanisms involving ethynylvinyl intermediate (formed via the Hofmann decomposition of the starting diiodide and the initially formed 1,4-adduct with a thiol) were discussed.     

A Facile synthesis of 3-alkylthio-(or arylthio-)pyridines and 3,5-bis(alkylthio)pyridines

3-Alkylthio- (or 3-arylthio-)pyridines and 3,5-bis(alkylthio)pyridine can be conveniently prepared by the reaction of 3-thiocyanato- or 3,5-bis(thiocyanato)pyridines with tri-n-butylphosphine in the presence of alcohol.     

Quantum-Chemical Calculation of 1-Bis(dimethlamino)-4-bis(trimethylsilyl)-2,3-diphospha-1,3-butadiene

According to the results of ab initio quantum-chemical calculation 1-bis(dimethylamino)-4-bis(trimethylsilyl-2,3-diphosphabuta-1,3-diene exists as an E-isomer where electronic delocalization occurs involving donor dimethylamino and acceptor trimethylsilyl groups and also the multiple P = C bonds.     

1,1,3,3-Tetramethyl-1,3-bis(vinyloxy-methyl)disiloxane

Conclusion 1,1,3,3-Tetramethyl-1,3-bis (vinyloxymethyl)disiloxane has been obtained for the first time from 1,3-bis(hydroxymethyl)tetramethyldisiloxane and butylvinyl ether in the presence of mercury acetate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1899–1900, August, 1984.