37385-32-3Relevant academic research and scientific papers
DONOR-AKZEPTOR SUBSTITUIERTE DIENOPHILE BEI DIELS-ALDER-REAKTIONEN MIT INVERSEM ELEKTRONENBEDARF
Meier, Anton,Sauer, Juergen
, p. 6855 - 6858 (1990)
1,1- and 1,2-Donor- and acceptor-substituted ethylenes are reacted as dienophiles with electron-poor dienes 1, 2 and 3.Kinetic data and regiochemistry studies are reported for these systems.
Boron Trifluoride-Mediated Cycloaddition of 3-Bromotetrazine and Silyl Enol Ethers: Synthesis of 3-Bromo-pyridazines
Schnell, Simon D.,González, Jorge A.,Sklyaruk, Jan,Linden, Anthony,Gademann, Karl
, p. 12008 - 12023 (2021/08/24)
Pyridazines are important scaffolds for medicinal chemistry or crop protection agents, yet the selective preparation of 3-bromo-pyridazines with high regiocontrol remains difficult. We achieved the Lewis acid-mediated inverse electron demand Diels-Alder reaction between 3-monosubstituted s-tetrazine and silyl enol ethers and obtained functionalized pyridazines. In the case of 1-monosubstituted silyl enol ethers, exclusive regioselectivity was observed. Downstream functionalization of the resulting 3-bromo-pyridazines was demonstrated utilizing several cross-coupling protocols to synthesize 3,4-disubstituted pyridazines with excellent control over the substitution pattern.
Gas-phase thermolysis of condensed-1,2,4-triazines: interesting routes toward heterocyclic ring systems
Al-Awadi, Hanan,Ibrahim, Maher R.,Al-Awadi, Nouria A.,Ibrahim, Yehia A.
, p. 12948 - 12953 (2008/03/28)
Gas-phase thermolysis of thieno[2,3-e][1,2,4]triazines gave benzonitrile, isothiazole, pyridazine, and thieno[2,3-d]thiazole derivatives. Similar transformation of benzo[1,2,4]triazine and phenanthro[9,10-e][1,2,4]triazine derivatives into their corresponding condensed thiazoles has been achieved by heating at 350 °C with sulfur. A mechanism for these pyrolytic transformations was proposed.
Pyridazines. Part 26: Efficient and regioselective Pd-catalysed arylation of 4-bromo-6-chloro-3-phenylpyridazine
Sotelo, Eddy,Ravin?a, Enrique
, p. 223 - 226 (2007/10/03)
The regioselective arylation at position 4 of 4-bromo-6-chloro-3-phenylpyridazine has been performed using a Suzuki cross-coupling reaction. This route allows access to a wide-ranging series of pharmacologically useful pyridazine derivatives and confirms
Synthesis and reactions of 3,4-dicarboxy-5,6-diphenylpyridazine
Shalaby, Alyaa A.,El-Shahawi, Manal,Shams, Nabil A.,Batterjee, Suzan
, p. 4141 - 4152 (2007/10/03)
Diethyl acetylenedicarboxylate 2 reacted with benzilmonohydrazone 1 to form 3,4-dicarboxycarbonyl-5,6-diphenylpyridazine 3, which upon alkaline hydrolysis gave the corresponding dicarboxylic acid 4. Decarboxylation of 4 gave 3,4-diphenylpyridazine 7. On t
Ab initio quantum-mechanical and experimental mechanistic studies of Diels-Alder reactions between unsubstituted and phenyl-substituted acetylenes and 1,2,4,5-tetrazines
Cioslowski, Jerzy,Sauer,Hetzenegger,Karcher,Hierstetter
, p. 1353 - 1359 (2007/10/02)
1,2,4,5-tetrazine (2a) undergoes thermal addition to phenylacetylene (1b) in dioxane with ΔH? = 15.8 kcal/mol and ΔS? = -31 cal/(mol·K). The activation parameters for the corresponding addition of 1b to 3-phenyl-1,2,4,5-tetrazine (2b
Synthesis of 3-Phenyl-5-silylpyridazines by Regioselective -Cycloadditions
Birkofer, Leonhard,Haensel, Edward,Steigel, Alois
, p. 2574 - 2585 (2007/10/02)
The cycloaddition of 3-phenyl-1,2,4,5-tetrazine (1) with the silylethyne 2a proceeds highly regioselectively to give 3-phenyl-5-(trimethylsilyl)pyridazine (3a).Similarly the reactions of 1 with the silylalkynes 2b - f, the silylalkynones 2g - i, and the s
Small Rings, 33. Attempts to Synthesize Diphenyltetrahedrane
White, Emil H.,Winter, Rudolph E. K.,Graeve, Rolf,Zirngibl, Ulrich,Friend, Earl W.,et al.
, p. 3906 - 3915 (2007/10/02)
Carbene 7, formed on photochemical or thermal excitation of (2,3-diphenyl-2-cyclopropen-1-yl)diazomethane (6i), splits mostly into two acetylenes 8 and 9 instead of undergoing an intramolecular cycloaddition.Photolysis of the Masamune ketone 16 depending on the reaction conditions gives either p-terphenyl or a mixture of the two cyclooctatetraens 18 and 19.The intermediate formation of tetrahedrane 10 would fit into the mechanistic picture of this fragmentation.
