23055-10-9Relevant articles and documents
Vinyltriphenylphosphonium salt mediated synthesis of 1,4-benzoxazine and coumarin derivatives
Yavari, Issa,Adib, Mehdi,Hojabri, Leila
, p. 6895 - 6899 (2002)
Protonation of the reactive 1:1 intermediate produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate by 2-aminophenol, 3-aminophenol, 4-aminophenol and 2-amino-3-hydroxypyridine leads to vinyltriphenylphosphonium salts, whi
Synthesis of extremely stable alkyl and hydride complexes of the type (R2NCS2)Pt(PEt3)R
Reger,Baxter,Garza
, p. 16 - 20 (1990)
The reaction of (R2NCS2)Pt(PEt3)Cl (R = Me, Et), prepared from [Pt(PEt3)Cl2]2 and Na(R2NCS2), with alkyllithium or Grignard reagents yields (R2NCS2)Pt(PEt3)(alkyl) (alkyl = Me, n-Pr, i-Pr, n-Bu, sec-Bu, i-Bu, t-Bu) complexes. These new alkylplatinum complexes are very stable and can be heated in solution at 100°C for extended periods without decomposition. The reaction of (R2NCS2)Pt(PEt3)Cl with NaBH4 yields the stable complexes (R2NCS2)Pt(PEt3)H, which decompose only slowly at 110°C. This hydride (R = Me) does not react with ethylene or phenylacetylene but will react with MeO2CC≡CCO2Me to yield a mixture of the E and Z isomers of (Me2NCS2)Pt(PEt3)(η1-C(CO2Me)=C(H)CO2Me ). The reaction of (R2NCS2)Pt(PEt3)Cl with AgBF4 and ethylene yields [R2NCS2)Pt(PEt3)(C2H4)]BF4, but these complexes are very unstable, decomposing rapidly in the absence of ethylene.
Microwave-specific acceleration of a retro-Diels-Alder reaction
Dudley, Gregory B.,Frasso, Michael A.,Stiegman, Albert E.
supporting information, p. 11247 - 11250 (2020/10/06)
A high-temperature retro-Diels-Alder reaction is accelerated by microwave (MW) heating to rates higher than expected based on Arrhenius kinetics and the measured temperature of the reaction mixture. Observations are consistent with selective MW heating of the polar reactant relative to other, less polar components of the reaction mixture.
Domino [4 + 1]-annulation of α,β-unsaturated δ-amino esters with Rh(ii)-carbenoids-a new approach towards multi-functionalized N-aryl pyrrolidines
Medvedev,Galkina,Klinkova,Giera,Hennig,Schneider,Nikolaev
supporting information, p. 2640 - 2651 (2015/06/08)
Catalytic decomposition of diazomalonates and other diazoesters using Rh(ii)- and Cu(ii)-complexes in the presence of α,β-unsaturated δ-(N-aryl)amino esters gives rise to the formation of multi-functionalized pyrrolidines with yields of up to 82%. The reaction apparently occurs as a domino process involving the initial N-ylide formation followed by intramolecular Michael addition to the conjugated system of amino esters to afford the pyrrolidine heterocycle. The whole process can also be classified as a [4 + 1]-annulation of the δ-amino α,β-unsaturated ester with the carbenoid intermediate. This journal is
Three-component reaction of triphenylphosphine, dialkyl acetylenedicarboxylates, and heterocyclic rings and the related iminophosphoranes
Anary-Abbasinejad, Mohammad,Hassanabadi, Alireza,Khaksari, Zahra
, p. 204 - 212 (2011/10/31)
Crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reaction of triphenylphosphine, dialkyl acetylenedicarboxylate, and NH acids, such as 2-aminothiazole and 2-aminobenzothiazole. These stabilized phosphoranes undergo a
Ruthenium- and rhodium-catalyzed carbenoid reactions of diazoesters in hexaalkylguanidinium-based ionic liquids
Large, Torsten,Mueller, Tobias,Kunkel, Helene,Buck, Stefan,Maas, Gerhard
experimental part, p. 347 - 353 (2012/07/14)
Hexaalkylguanidinium-based room-temperature ionic liquids were investigated as solvents for the cyclopropanation of styrene with diazoacetates catalyzed by Rh2(OAc)4 or [Ru2(μ-OAc) 2(CO)4]n. While the yields of the formed cyclopropanes are much lower compared to the reactions performed in dichloromethane, the diastereomeric ratio is not significantly affected by the change of the reaction medium. Immobilization of the catalysts is only partially successful. In contrast to this intermolecular reaction, the Ru-catalyzed formation of a β-lactam by an intramolecular carbenoid C-H insertion of an α-methoxycarbonyl-α-diazoacetamide occurs in high yield, similar to the Rh2(OAc)4-catalyzed reaction. The cis → trans isomerization of the resulting 1-tert-butyl-3-methoxycarbonyl-4-phenyl-azetidin- 2-one is accelerated in the ionic liquid N,N-dibutyl-N',N'-diethyl-N'',N''- dihexylguanidin-ium triflate.
Effect of imidazolium salts on the catalytic reaction of 1,3-dioxolanes with methyl diazoacetate
Ivanova,Sultanova,Zlotskii
experimental part, p. 106 - 108 (2011/06/18)
Effect of imidazolium salts, [bmim]+Cl-, [bmim] +BF4 -, and [bmim]+PF6 -, on the reaction of 1,3-dioxolanes with methyl diazoacetate in the presence of copper-containing catalysts was studied. The product composition was found to depend on the reaction conditions and the nature and ratio of components of the catalytic system.
Transfer semihydrogenation of alkynes catalyzed by a zero-valent palladium N-heterocyclic carbene complex
Hauwert, Peter,Maestri, Giovanni,Sprengers, Jeroen W.,Catellani, Marta,Elsevier, Cornelis J.
, p. 3223 - 3226 (2008/12/23)
(Chemical Equation Presented) Beyond Lindlar and without hydrogen: Transfer hydrogenation of internal alkynes catalyzed by a palladium(0) catalyst containing an N-heterocyclic carbene ligand gives Z alkenes without over-reduction to alkanes (see scheme). Contrary to most transfer hydrogenations, ketones are not reduced. As such, this is the first catalyst that shows excellent stereo- and chemo-selectivity for the semihydrogenation of alkynes without the need for hydrogen gas.
New catalytic system Cu(OAc)2-2,4-lutidine-ZnCl2 for olefin cyclopropanation with methyl diazoacetate
Gareev,Sultanova,Biglova,Dokichev,Tomilov
experimental part, p. 1784 - 1786 (2011/04/23)
A new efficient catalytic system consisting of Cu(OAc)2, 2,4-lutidine, and ZnCl2 was found for the cyclopropanation of unsaturated compounds with methyl diazoacetate. In the case of conjugated dienes, the process occurs regioselectively at the most alkylated C=C bond.
Synthesis of sulfur-containing aryliminophosphoranes
Yavari, Issa,Zabarjad-Shiraz, Nader,Bijanzadeh, Hamid R.
, p. 1381 - 1386 (2007/10/03)
Stabilized phosphoranes, obtained from the three-component reaction between dialkyl acetylenedicarboxylates and arylsulfonamides in the presence of triphenylphosphine, undergo a smooth intramolecular reaction, in boiling toluene to produce sulfur-containing iminophosphoranes in excellent yields.
