14164-34-2Relevant academic research and scientific papers
volution of Hydrogen in the Reaction of Hydroheteroaromatic Compounds with Dehydrogenating Agents
Morkovnik, A. S.,Ivakhnenko, E. P.,Bogachev, Yu. G.,Tertov, B. A.,Berberova, N. T.,Okhlobystin, O. Yu.
, p. 168 - 173 (1988)
The yields of molecular hydrogen in the reactions of benzimidazolines 1,2-dihydropyrimidines with a number of dehydrogenating agents have been determined.The formation of hydrogen is due to breakdown of the cation-radicals of the hydrohetarenes formed in
Metalation of Aryl-bis(3-alkyl-5-methylpyrazol-1-yl)- methane (Alkyl=Me, Ad; Aryl=Ph, C6H4-2?OH) with NaN(SiMe3)2, KN(SiMe3)2, and Ca{N(SiMe3)2}2
G?rls, Helmar,Krieck, Sven,Müller, Christoph,Mandel, Miles J.,Westerhausen, Matthias
, (2022/02/03)
Deprotonation of phenyl-bis(3,5-dimethylpyrazolyl)methane (HC(Ph)(PzMe2)2, 1 a) with [(thf)2Ca{N(SiMe3)2}2] in THF at ?40 °C yields heteroleptic [(thf)2Ca{N(SiMe3)2}{C(Ph)(PzMe2)2}] (2 a) and finally homoleptic [(thf)Ca{C(Ph)(PzMe2)2}2] (2 b). However, these complexes degrade at room temperature to calcium bis(pyrazolate) and 2-phenyl-4,6-dimethylpyrimidine (3 a). This degradation is accelerated when bulky phenyl-bis(3-adamantyl-5-methylpyrazolyl)methane (HC(Ph)(PzAd,Me)2, 1 b) is treated similarly and 2-phenyl-4-adamantyl-6-methylpyrimidine (3 b) forms quickly. Sodiation of 1 a and 1 b with NaN(SiMe3)2 yields [{HC(Ph)(PzMe2)2}Na{C(Ph)(PzMe2)2}] (4 a) and [{HC(Ph)(PzAd,Me)2}Na{C(Ph)(PzAd,Me)2}] (4 b). The stronger metalation reagent benzylpotassium is able to quantitatively deprotonate 1 b leading to dinuclear [K{C(Ph)(PzAd,Me)2}]2 (4 c). The metathetical approach and the reaction of 4 c with metal(II) halides of Mg, Ca and Zn again leads to degradation and formation of pyrimidine 3 b. This decomposition of the ligand can be circumvented when the sidearm contains the anionic charge. Thus, 2-hydroxyphenyl-bis(3-adamantyl-5-methylpyrazol-1-yl)methane (1 c) reacts with [(thf)2Ca{N(SiMe3)2}2] in THF to the homoleptic complex [(thf)4Ca{O?C6H4?CH(PzAd,Me)2}] (2 c). In this complex, THF and pyrazolyl bases compete in the coordination sphere and preparation of a heteroleptic complex fails. To avoid the binding competition between THF and pyrazolyl bases and to stabilize heteroleptic calcium complexes, the reaction has been repeated in toluene yielding [Ca{N(SiMe3)2}{O?C6H4?CH(PzAd,Me)2}]2 (2 d).
Electronic absorption and emission properties of bishydrazone [2?×?2] metallosupramolecular grid-type architectures
Holub, Jan,Santoro, Antonio,Lehn, Jean-Marie
supporting information, p. 223 - 231 (2019/06/07)
Several ditopic ligands containing two tridentate bishydrazone coordination subunits and their Zn(II) and Cd(II) [2 × 2] grid-type complexes were prepared and their photoluminescent properties studied. A special attention was devoted to the influence of the orientation of the hydrazone group N–N[dbnd]in the core of the ligands and their complexes. Its reversal from [pyridine[dbnd]N–N–pyrimidine] (L1) to [pyridine–N–N[dbnd]pyrimidine] (L2) has a strong impact on the observed absorption and emission behaviour of particular ligands (L1 and L2) as well as of their [2 × 2] grid assemblies. The further lateral functionalization of the ligands led to different emission quantum yields of the resulting grids, while their emission and absorption spectra varied very little. The simplest derivative L1 turned out to have the best performance with, for its Zn(II) complex, relatively high quantum yield 60%.
The phosphorescent pyrimidine iridium complex production device
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Paragraph 0030; 0031, (2018/04/01)
The invention belongs to the technical field of chemical engineering equipment, and relates to a device for producing a phosphorescent pyrimidine iridium complex. The device comprises a reactor, wherein a reflux cooling pipe is connected to the top of the reactor and is connected with a condenser; the condenser is connected with one end of a U-shape tube, and the other end of the U-shaped tube is connected to the top of the reactor; the bottom of the U-shaped tube is connected to the top of a rinsing tank; the reactor is connected with a nitrogen storage tank; the bottom of the reactor is successively connected with a filter and a first pump; the first pump is respectively connected to the top of the rinsing tank and the top of an ester washing tank; the bottom of the rinsing tank is connected to the top of the ester washing tank; the bottom of the ester washing tank is connected with the top of a chromatographic column the bottom of which is connected with a concentrator; and the concentrator is connected with a dryer. The device is designed specially for producing a phosphorescent pyrimidine iridium complex, the reaction process is sealed and safe, and operations of multiple suction filtering, rinsing, organic solvent cleaning, chromatography and concentration drying can be finished, thus all production steps can be completed in one device.
Iron Catalysis for Modular Pyrimidine Synthesis through β-Ammoniation/Cyclization of Saturated Carbonyl Compounds with Amidines
Chu, Xue-Qiang,Cao, Wen-Bin,Xu, Xiao-Ping,Ji, Shun-Jun
, p. 1145 - 1154 (2018/06/18)
An efficient method for the modular synthesis of various pyrimidine derivatives by means of the reactions of ketones, aldehydes, or esters with amidines in the presence of an in situ prepared recyclable iron(II)-complex was developed. This operationally simple reaction proceeded with broad functional group tolerance in a regioselective manner via a remarkable unactivated β-C-H bond functionalization. Control experiments were performed to gain deep understanding of the mechanism, and the reactions are likely to proceed through a designed TEMPO complexation/enamine addition/transient α-occupation/β-TEMPO elimination/cyclization sequence.
Novel multi-component syntheses of pyrimidines using β-CD in aqueous medium
Rakhi, Chowrasia,Ramesh, Katla,Darbem, Mariana P.,Branquinho, Tabata A.,De Oliveira, Aline Rufino,Manjari, Padma Sunitha,Domingues, Nelson Luís C.
supporting information, p. 1656 - 1660 (2016/04/04)
Using β-cyclodextrin (β-CD) as a catalyst pyrimidine derivatives were synthesized for the first time in aqueous medium. β-CD is a recyclable, inexpensive, economically viable, non-toxic, and readily available material. Various aldehydes were used with amm
Greener [3+3] tandem annulation-oxidation approach towards the synthesis of substituted pyrimidines
Vadagaonkar, Kamlesh S.,Kalmode, Hanuman P.,Prakash, Sattey,Chaskar, Atul C.
, p. 3639 - 3645 (2015/05/20)
An economical and green synthesis of partly and fully substituted pyrimidines is described using α,β-unsaturated ketones and benzamidine hydrochloride using greener and recyclable choline hydroxide (ChOH) as both a catalyst and a reaction medium. The remarkable features of this method are mild reaction conditions, short reaction times, easy workup procedure, recyclability of the catalyst and excellent yields of the products. The reaction involves a [3+3] annulation-oxidation sequence and the protocol is useful for synthesizing a broad range of biologically significant pyrimidine derivatives.
Metal-free synthesis of 2,4,6-trisubstituted pyrimidines using α,β-unsaturated ketones and benzamidine via tandem annulation-oxidation pathway
Vadagaonkar, Kamlesh S.,Kalmode, Hanuman P.,Murugan, Kaliyappan,Chaskar, Atul C.
, p. 447 - 458 (2015/07/28)
A tandem metal-free synthesis of partly and fully substituted pyrimidines has been accomplished from α,β-unsaturated ketones and benzamidine in presence of triethyl amine. The reaction proceeds via [3+3] annulation-oxidation sequence and the protocol has
Ligand-accelerated iron- and cobalt-catalyzed cross-coupling reactions between N-heteroaryl halides and aryl magnesium reagents
Kuzmina, Olesya M.,Steib, Andreas K.,Markiewicz, John T.,Flubacher, Dietmar,Knochel, Paul
supporting information, p. 4945 - 4949 (2013/06/04)
Quinoline and isoquinoline dramatically increase the rate and yield of Fe- and Co-catalyzed cross-coupling reactions. This new catalytic process extends the scope of such cross-coupling reactions to include complex functional groups and allows heteroaryl-
Iron-catalyzed cross-coupling of N-heterocyclic chlorides and bromides with arylmagnesium reagents
Kuzmina, Olesya M.,Steib, Andreas K.,Knochel, Paul,Flubacher, Dietmar
supporting information, p. 4818 - 4821,4 (2012/12/12)
A simple, practical iron salt catalyzed procedure allows fast cross-couplings of N-heterocyclic chlorides and bromides with various electron-rich and -poor arylmagnesium reagents. A solvent mixture of THF and tBuOMe is found to be essential for achieving high yields mainly by avoiding homocoupling side reactions.
