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1.
Chemoselective Staudinger‐Phosphite Reaction on the Azido Groups of 2,4,6‐Triazido‐3,5‐dibromopyridine
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Sergei V. Chapyshev Alexander V. Chernyak Igor K. Yakushchenko 《Journal of heterocyclic chemistry》2016,53(3):970-974
2,4,6‐Triazido‐3,5‐dibromopyridine reacts with an equimolar amount of triethyl phosphite in ether at room temperature chemoselectively on the γ‐azido group to form 2,6‐diazido‐3,5‐dibromo‐4‐triethoxyphosphoriminopyridine as a single product. The latter adds another molecule of triethyl phosphite to give a mixture of 6‐azido‐2,4‐bis(triethoxyphosphorimino)‐3,5‐dibromopyridine and its tetrazolo[1,5‐a]pyridine isomer, the acidic hydrolysis of which affords 6‐azido‐2,4‐bis(diethoxyphosphoramino)‐3,5‐dibromopyridine. The study shows that the Staudinger‐phosphite reactions with heterocyclic polyazides occur selectively on the most electron‐deficient azido groups, opening up new prospects for preparation of new polyfunctional heterocyclic compounds. 相似文献
2.
A sulfated choline‐based ionic liquid [Ch‐OSO3H] was prepared and used as a novel catalyst for the synthesis of α‐aminophosphonates via a one‐pot three‐component reaction with aldehydes, amines, and triethyl phosphite/diethyl phosphite at room temperature under solvent‐free conditions or in aqueous media. The reaction was completed in short times and products could be simply separated from the reaction mixture in good to excellent yields. The catalyst could be recycled and reused for several times without noticeably reducing catalytic activity. 相似文献
3.
Biswanath Das Avula Satya Kumar Jayprakash Narayan Kumar 《Helvetica chimica acta》2011,94(8):1459-1462
(α‐Aminoalkyl)phosphonates have efficiently been synthesized by multicomponent reaction of aldehydes, amines, and triethyl phosphite in the presence of 2,4,6‐trichloro‐1,3,5‐triazine at room temperature. The products are formed in high yields (83–91%) within 0.5–1 h. 相似文献
4.
A convenient method has been developed to synthesize diaryl arylphosphonates from triaryl phosphites, triethyl phosphite, and aromatic halides. The new method relies on the triethyl phosphite assisted nickel catalyzed Arbuzov reaction and can be applied to synthesize certain diaryl alkylphosphonates without catalysts. 相似文献
5.
5‐{[(1E)‐(4‐methoxyphenyl)methylene]amino}‐1,3,4‐thiadiazole‐2‐thiol ( 1a ) reacts with trialkyl phosphites ( 2a–c ) to give the respective dialkyl phosphonate adducts ( 4a–c ). On the other hand, the reactions of trisdialkylaminophosphines ( 3a,b ) with 1a , 5‐{[(1E)‐(4‐phenyl)methylene]amino}‐1,3,4‐thiadiazole‐2‐thiol ( 1b ) yield the corresponding open dipolar structures 6a–c . In the case of the reaction of triethyl phosphite ( 2a ) with 1b , both the dialkyl phosphonate adduct ( 7 ) and the dipolar product ( 8a ) are obtained. Moreover, triisopropyl phosphite ( 2c ) reacts with 1b to give both the S‐alkyl and the N‐alkyl phosphonate adducts ( 9a,b ), respectively. Mechanisms are proposed to explain the formation of the new products, and their structures were confirmed on the basis of elemental analysis and spectral studies. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:594–601, 2001 相似文献
6.
Mohammed Ghalib Basit Niaz Peter G. Jones Joachim W. Heinicke 《Heteroatom Chemistry》2013,24(6):452-459
The phosphonylation of 2‐bromo‐formylanilides 1 with triethyl phosphite in the presence of preformed Pd(0)(triethyl phosphite)n catalyst furnished 2‐phosphono‐formanilides 2 in good yields. Reduction with excess LiAlH4 provided mainly N‐methyl‐2‐phosphinoanilines 3 and minor amounts of 1,2‐unsubstituted benzazaphospholes 4 . N‐Methyl‐1,3‐benzazaphospholes 5 were synthesized by the cyclocondensation of 3 with dimethylformamide dimethylacetal (DMFA). A more convenient route to 5 , avoiding the chromatographic separation of 4 , is the reduction of 1 to 2‐bromo‐N‐methylaniline 6 , followed by phosphonylation to 7 , LiAlH4 reduction, and cyclization with DMFA. The coordination properties at σ2P of benzazaphospholes are characterized by structural data obtained by the crystal structure analysis of ( 5b )W(CO)5. 相似文献
7.
NbCl5 has been found to be a very effective catalyst for the synthesis of a variety of α‐aminophosphonates through the Kabachnik–Fields reaction of carbonyl compound, amine and diethyl phosphite under solvent‐free conditions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
8.
A highly efficient one‐pot three‐component reaction of aldehydes or ketones, amines, and trimethyl or triethyl phosphite catalyzed by p‐dodecylbenzensulfonic acid is developed for the synthesis of α‐aminophosphonates at room temperature in water. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:174–178, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21079 相似文献
9.
Alajos Grün Istvn Gbor Molnr Bla Bertk Istvn Greiner Gyrgy Keglevich 《Heteroatom Chemistry》2009,20(6):350-354
The synthesis of hydroxy‐methylenebisphosphonates ( 2a–c ) by the addition of dialkyl phosphite to the carbonyl group of the corresponding α‐oxophosphonate ( 1a–c ) was studied under microwave irradiation (MW) and solventless conditions in the presence of dialkylamine as the catalyst. After optimization, products 2a and 2b were obtained selectively and in good yields avoiding the formation of the phosphonate‐phosphate by‐product ( 3a and 3b ) that is the result of a rearrangement. The MW‐assisted synthesis of hydroxybisphosphonates ( 2a and 2b ) offers complete conversions and a chemoselectivity of 100% as compared to the not so efficient thermal reaction. At the same time, the phenyl‐substituted methylenebisphosphonate 2c could be obtained in only 75% selectivity. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:350–354, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20558 相似文献
10.
Andrey A. Prishchenko Mikhail V. Livantsov Olga P. Novikova Ludmila I. Livantsova Gleb M. Averochkin Valery S. Petrosyan 《Heteroatom Chemistry》2015,26(6):405-410
The convenient methods for the synthesis of new trimethylsilyl esters of aminomethylenediphosphonic acids are elaborated. The new substituted N‐formylaminomethylenediphosphonates are obtained via the interaction of trimethylsilyl esters of methylenediphosphonic acids with a mixture of triethyl orthoformate and ethanol. Also boron trifluoride–diethyl etherate as an effective catalyst is used for the interaction of hydrochlorides of ethoxymethylene imines with diethyl trimethylsilyl phosphite. The corresponding aminomethylenediphosphonic acids are presented. 相似文献
11.
Gyrgy Keglevich Erika Blint Rka Kangyal Mria Blint Mtys Milen 《Heteroatom Chemistry》2014,25(4):282-289
α‐Aminophosphonates may be synthesized by the three‐component condensation of oxo‐compounds, amines, and dialkyl phosphites or trialkyl phosphites. In the latter case, mostly water is the reaction medium and a catalyst is also needed. This approach has been studied critically by us, exploring the background of this version of the Kabachnik–Fields condensation. The possibilities for the Kabachnik–Fields condensation of benzaldehyde, benzylamine, and triethyl phosphite or diethyl phosphite including the accomplishment in water were studied in detail. 相似文献
12.
Gyrgy Keglevich Alajos Grün Adrienn Blcskei Lszl Drahos Mrta Kraszni Gyrgy T. Balogh 《Heteroatom Chemistry》2012,23(6):574-582
A series of substituted diethyl arylphosphonates was synthesized by the microwave‐assisted Arbuzov reaction of triethyl phosphite and aryl bromides in the presence of NiCl2 as the catalyst under solvent‐free conditions in good yields. The resulting phosphonates were hydrolyzed to the corresponding arylphosphonic acids whose acidity was evaluated by physicochemical methods. 相似文献
13.
O,O'Diethyl acetals were prepared in high yields under mild conditions via the reaction of triethyl orthoformate with aldehydes and ketones in absolute ethanol in the presence of as low as 0.1 tool% of Yb(OTf)3. Using the same catalyst in THF-H2O, these O,O'-diethyl acetals could be converted to the corresponding carbonyl compounds efficiently. This new protection-deprotection protocol presents the advantages of ease of execution, high efficiency and good chemoselectivity. 相似文献
14.
Zyta Ziora Alina Maly Barbara Lejczak Pawel Kafarski Jolanta Holband Grayna Wjcik 《Heteroatom Chemistry》2000,11(3):232-239
Reaction of commercially available trialkyl phosphites with N‐phthalylamino acids gave mixtures of seven products, whereas the same reaction carried out with pure triethyl phosphite yielded only the desired 2‐(N‐phthalylamino)‐1‐oxoalkanephosphonates. These compounds underwent rearrangement to the same types of products that were obtained with the commercial phosphites. This latter series of reactions was promoted by the presence of dialkyl phosphites. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:232–239, 2000 相似文献
15.
Zishuo Zhou Hongfei Han Zijing Chen Rui Gao Zhen Liu Jie Su Nana Xin Xiaobing Yang Liangbing Gan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(49):17854-17858
Open‐cage fullerenes with a 19‐membered orifice were prepared in three steps from C60. The key step for cage‐opening is aniline mediated ring expansion of a fullerene‐mixed peroxide with a ketolactone moiety on the orifice. Release of ring strain on the spherical fullerene cage served as the main driving force for the efficient cage‐opening sequence. Encapsulation of oxygen could be achieved at room temperature under moderate pressure (50 atm) and the encapsulated oxygen could be released slowly under ambient conditions. The activation energy of the oxygen‐releasing process is 18.8 kcal mol?1 and the half‐life at 37 °C was 73 min, which makes this open‐cage fullerene derivative a potential oxygen‐delivery material. 相似文献
16.
氮气保护条件下,纳米铝在0.1 N NH4Cl溶液中,能有效地促进羰基化合物与烯丙基溴进行Barbier-Grignard型烯丙基化反应,得到相应高烯丙醇。芳香族醛或酮的烯丙基化产率较高,而脂肪族羰基化合物反应产率低,反应产率受羰基空间位阻影响大,在同样条件下,邻羟基羰基化合物烯丙基化产物主要是赤式-邻二醇。 相似文献
17.
An efficient and environmentally friendly procedure for the one-pot synthesis of tetrahydropyrimidinones from aldehydes, β-diketones and urea/thiourea by using magnesium bromide as an inexpensive and easily available catalyst under solvent-free conditions was described. Compared with the classical Biginelli reaction conditions, this new method has the advantage of good to excellent yields (74%-94%) and short reaction time (45-90 min). The structure of the Biginelli reaction product from β-diketone, salicylaldehyde and urea has been proposed to possess an oxygen-bridge by cyclization (intramolecular Michael-addition). 相似文献
18.
Design,Synthesis, and Self‐Assembly Behavior of Liquid‐Crystalline Bis‐[60]Fullerodendrimers
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Virginie Russo Pauline Pieper Dr. Benoît Heinrich Dr. Bertrand Donnio Prof. Robert Deschenaux 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17366-17376
Bis‐[60]fullerodendrimers were synthesized by assembling [60]fullerene‐containing type I (terminal olefin) and type II (α,β‐unsaturated carbonyl olefin) olefins through the olefin cross‐metathesis reaction. The synthetic modular approach developed in this study allowed the preparation of mono‐[60]fullerodendrimers and their [60]fullerene‐free analogues. First‐ and second‐generation poly(aryl ester) dendrons carrying cyanobiphenyl mesogens were used as liquid‐crystalline promoters. The liquid‐crystalline properties were studied by polarized optical microscopy, differential scanning calorimetry, and small‐angle X‐ray scattering. In agreement with the nature and structure of the dendrimers, nematic, smectic, and multisegregated lamellar phases were observed. Owing to its versatility and tolerance towards many functional groups, olefin cross‐metathesis proved to be a reaction of choice for the elaboration of molecular materials with complex architectures. 相似文献
19.
Prof. Dr. Lukas Hintermann Dr. Jens Ackerstaff Dr. Florian Boeck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2311-2321
Cinchona alkaloids catalyze the oxa‐Michael cyclization of 4‐(2‐hydroxyphenyl)‐2‐butenoates to benzo‐2,3‐dihydrofuran‐2‐yl acetates and related substrates in up to 99 % yield and 91 % ee (ee=enantiomeric excess). Catalyst and substrate variation studies reveal an important role of the alkaloid hydroxy group in the reaction mechanism, but not in the sense of a hydrogen‐bonding activation of the carbonyl group of the substrate as assumed by the Hiemstra–Wynberg mechanism of bifunctional catalysis. Deuterium labeling at C‐2 of the substrate shows that addition of RO? H to the alkenoate occurs with syn diastereoselectivity of ≥99:1, suggesting a mechanism‐based specificity. A concerted hydrogen‐bond network mechanism is proposed, in which the alkaloid hydroxy group acts as a general acid in the protonation of the α‐carbanionic center of the product enolate. The importance of concerted hydrogen‐bond network mechanisms in organocatalytic reactions is discussed. The relative stereochemistry of protonation is proposed as analytical tool for detecting concerted addition mechanisms, as opposed to ionic 1,4‐additions. 相似文献
20.
V. M. Ismailov G. E. Allakhverdieva N. D. Sadykhova I. A. Mamedov N. N. Yusubov 《Russian Journal of General Chemistry》2020,90(1):89-92
Addition of ethanol and diethyl phosphonate to the carbonyl group of 2,2-dichloro-2-(diethoxyphosphoryl)-acetaldehyde has been studied, and the corresponding α-chloro ether, acetal, and phosphorylated metrifonate have been obtained. α,α-Dichloro-α-phosphoryl carbonyl compounds have been found to undergo haloform cleavage by the action of bases. Perkow reaction of mono- and dichloro(diethoxyphosphoryl)acetaldehydes with triethyl phosphite afforded diethyl 2-(diethoxyphosphoryl)ethenyl phosphates. 相似文献