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1.
Catalytic Asymmetric Synthesis of 3‐Indolyl Methanamines Using Unprotected Indoles and N‐Boc Imines under Basic Conditions
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Prof. Dr. Takayoshi Arai Junki Kakino 《Angewandte Chemie (International ed. in English)》2016,55(49):15263-15267
A chiral imidazolidine‐containing NCN/Pd‐OTf catalyst ( C4 ) promoted the nucleophilic addition of unprotected indoles to N‐Boc imines. Using sulfinyl amines as the N‐Boc imine precursors, the combined use of C4 with K2CO3 activated the NH indoles to give chiral 3‐indolyl methanamines with up to 98 % ee. Compared with conventional acid‐catalyzed Friedel–Crafts reactions, this reaction proceeds under mildly basic conditions and is advantageous for the use of acid‐sensitive substrates. 相似文献
2.
《国际化学动力学杂志》2017,49(8):576-583
The nucleophilic addition reactions of N1‐methyl‐4‐nitro‐2,1,3‐benzoselenadiazolium tetrafluoroborate 1 with aliphatic amines 2a–c (diethylamine 2a , dipropylamine 2b, and allylamine 2c ) have been kinetically studied by UV–vis spectroscopy in acetonitrile solution at 20°C. The kinetic data have been analyzed, using the Mayr equation, allowing the quantification of the electrophilicity parameter (E ) value of benzoselenadiazolium cation 1 (E = −14.72). The reliability of parameter E has been reasonably verified by comparison of calculated and experimental second‐order rate constants for the reactions of cation 1 with other amines 2d–f (pyrrolidine 2d , piperidine 2e, and morpholine 2f ) under the same conditions as those of the amines 2a–c . A linear Brönsted plot (R 2 = 0.9945) with a β nuc value of 0.55 has been obtained for the reactions of 1 with the secondary amines employed in the present work. Interestingly, satisfactory correlation between the log values of measured and calculated rate constants with a slope very close to unity has been obtained and discussed. 相似文献
3.
V. A. Chornous A. M. Grozav E. B. Rusanov A. M. Nesterenko M. V. Vovk 《Russian Journal of Organic Chemistry》2011,47(5):702-709
1-Alkyl(aryl)imidazolidine-2,4-diones reacted with Vilsmeier-Haack reagent affording 1-alkyl(aryl)-2,4-dichloro-1H-imidazole-5-carbaldehydes whose reactions with sodium azide, sodium alkoholates, with phenols, thiols, and secondary cycloalkylamines
led to the substitution of chlorine in the position 2 of the imidazole ring. The reaction with primary amines resulted in the condensation products at the aldehyde group. 相似文献
4.
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
5.
Under mild reaction conditions, the thiocyanato group is selectively transferred from 1‐methyl‐3‐phenyl‐3‐thiocyanato‐1H,3H‐quinoline‐2,4‐dione ( 3 ) to some nucleophiles. Aliphatic primary and secondary amines are converted to S‐cyanothiohydroxylamines, anilines afford p‐thiocyanatoanilines, Wittig reagent is thiocyanated in α‐position, and thiols are oxidized to disulfides. 相似文献
6.
Synthesis of Analogues of Indole Alkaloids from Sea Sponges – Aplysinopsins by the Reaction of Amines with (4Z)‐4‐[(1H‐indol‐3‐yl)‐methylene]‐1,3‐oxazol‐5(4H)‐ones
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A new two‐step approach toward the synthesis of aplysinopsin analogues 5‐(1‐R‐1H‐indol‐3‐ylmethylene)‐2‐aryl‐3,5‐dihydroimidazol‐4‐ones consisting in obtaining and reaction of 4‐(1‐R‐1H‐indol‐3‐ylmethilene)‐2‐Ar‐4H‐oxazol‐5‐ones with amines was developed. The configuration of starting compounds and final products was determined by 13С and 1H‐nmr spectroscopy. 相似文献
7.
The carbodiimides 4 , obtained from aza‐Wittig reactions of iminophosphorane 3 with aromatic isocyanates, reacted with secondary amines, phenols or alcohols in the presence of catalytic amounts of K2CO3 or sodium alkoxide to give 2‐substituted benzofuro[3,2‐d]pyrimidin‐4(3H)‐ones 6 . However, when 2,2′‐iminobis[ethanol] was used, the unexpected ring opening product 7 was formed instead of 6 . Reaction of 4 with primary amines RNH2 (R=Et, Pr, Bu, etc.) gave guanidine intermediates 8 , which were further treated with EtONa to give only one regioisomer 9 via a base catalyzed cyclization. However, another regioisomer 11 was obtained when NH3 or ‘small’ amines RNH2 (R=Me, NH2) were used in the absence of EtONa via a spontaneous cyclization of 8 . 相似文献
8.
The chemical reactivity of 3‐nitrochromone ( 1 ) was studied towards some nucleophilic reagents. Reaction of 3‐nitrochromone ( 1 ) with some carbon nucleophiles revealed existence of ring‐opening ring‐closure reactions, and the mode of cyclization depends on the nucleophile used. Treatment of 3‐nitrochromone ( 1 ) with malononitrile and ethyl cyanoacetate produced benzoxocinone derivatives 2 and 3 , respectively. Boiling compound 1 with cyanoacetamide and 2‐aminoprop‐1‐ene‐1,1,3‐tricarbonitrile afforded pyridine derivatives 4 and 5 , respectively. Reaction of compound 1 with 1H‐benzimidazol‐2‐ylacetonitrile, 5‐amino‐2,4‐dihydro‐3H‐pyrazol‐3‐one, and dimedone led to pyrido[1,2‐a]benzimidazole 6 , pyrazolo[3,4‐b]pyridine 7 , and chromenone 8 , respectively. Treating 3‐nitrochromone ( 1 ) with heterocyclic amines gave enaminones 11 and 12 via nucleophilic attack at C‐2 position with ring opening. The structures of the newly synthesized products were deduced on the basis of their analytical and spectral data. 相似文献
9.
Cu‐Catalyzed Aerobic Oxidative Cyclizations of 3‐N‐Hydroxyamino‐1,2‐propadienes with Alcohols,Thiols, and Amines To Form α‐O‐, S‐, and N‐Substituted 4‐Methylquinoline Derivatives
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Pankaj Sharma Prof. Dr. Rai‐Shung Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(12):4590-4594
A one‐pot, two‐step synthesis of α‐O‐, S‐, and N‐substituted 4‐methylquinoline derivatives through Cu‐catalyzed aerobic oxidations of N‐hydroxyaminoallenes with alcohols, thiols, and amines is described. This reaction sequence involves an initial oxidation of N‐hydroxyaminoallenes with NuH (Nu=OH, OR, NHR, and SR) to form 3‐substituted 2‐en‐1‐ones, followed by Brønsted acid catalyzed intramolecular cyclizations of the resulting products. Our mechanistic analysis suggests that the reactions proceed through a radical‐type mechanism rather than a typical nitrone‐intermediate route. The utility of this new Cu‐catalyzed reaction is shown by its applicability to the synthesis of several 2‐amino‐4‐methylquinoline derivatives, which are known to be key precursors to several bioactive molecules. 相似文献
10.
The kinetics of the thermal rearrangement 4‐ethyl‐3,5‐diphenyl‐4H‐1,2,4‐triazoles, 1 , to the corresponding 1‐ethyl‐3,5‐diphenyl‐1‐alkyl‐1H‐1,2,4‐triazoles, 2 , was studied in 15‐Crown‐5 and octadecane at 330 °C. The reaction was very slow in octadecane but proceed well in 15‐Crown‐5. The reaction order for the reaction was not constant but changed from an initial second order rate law towards a first order rate law as the reaction progressed. This was confirmed by the concentration dependent reaction order, nc, which was larger than the time dependent rate law, nt. The rationale for the observation was, that at high substrate concentrations the reaction order was second order while at lower concentrations a competing solvent assisted reaction plays an increasing important role. The data were in agreement with a mechanism in which the neutral 4‐alkyl‐triazoles in an intermolecular nucleophilic displacement reaction form a triazolium triazolate, which in a subsequent nucleophilic reaction gives the observed product. 相似文献
11.
Aleksei B. Sheremetev Igor L. Yudin Nadezhda V. Palysaeva Kyrill Yu. Suponitsky 《Journal of heterocyclic chemistry》2012,49(2):394-401
The annulation reaction of vinamidinium salt containing nitrofurazanyl moiety at the β‐position gives access to the corresponding pyrazole. At nitration, two nitro groups were installed to the pyrazole ring. The synthesized 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan 13 is strong NH acid and a new family energetic salts was prepared by direct neutralization with high nitrogen bases. Compound 13 crystallizes in the monoclinic space group P21/c, and charaterized by high density of 1.979 g/cm3 (at 100 K). J. Heterocyclic Chem., (2012). 相似文献
12.
Diastereoselective Nucleophilic Ring‐Opening Reactions of 2,6‐Diazasemibullvalenes for the Synthesis of Diverse Functionalized Δ1‐Bipyrroline Derivatives
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Dr. Shaoguang Zhang Ming Zhan Prof. Dr. Wen‐Xiong Zhang Prof. Dr. Zhenfeng Xi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9744-9752
Nucleophilic ring‐opening reactions of 2,6‐diazasemibullvalenes (NSBVs) were investigated. Different types of nucleophile (alcohols, phenols, thiols, carboxylic acids, water, enols, amines, indoles, metal‐halide salts, sodium azide, organozinc compounds, lithium alkynethiolate, and sulfoxonium ylides) were used to afford diverse functionalized Δ1‐bipyrroline derivatives in good yields with high regio‐ and diastereoselectivity. Most of the reactions featured milder conditions and higher reactivity relative to those for common aziridine derivatives, probably because of the rigid ring system and substitution patterns of NSBVs. 相似文献
13.
《Journal of heterocyclic chemistry》2017,54(6):3030-3041
A simple and efficient domino reaction for synthesis of 7‐chloro‐2‐arylthieno[3,2‐b ]pyridin‐3‐ols ( 3 ) followed by derivatization into their corresponding aminoaryl ( 7a–7j ), aryloxy ( 9a–9c ), and thioaryloxy derivatives ( 8a–8k )is presented. The synthesis includes thioalkylation on 3‐position of methyl 4‐chloropicolinate ( 1 ) followed by in situ cyclization to give 7‐chloro‐2‐arylthieno[3,2‐b ]pyridin‐3‐ols ( 3 ). The substitution of the chloro group with amines, phenols and thiophenols afforded the corresponding derivatives. 相似文献
14.
Facile synthetic routes for the preparation of some new 4-amino-3,5-dinitropyridine derivatives have been revealed. Nitration of 2-chloropyridin-4-amine (1) as a starting material, in an unexpected one-step reaction, to give dinitrated derivatives, followed by nucleophilic substitution reactions with sodium azide, potassium fluoride, ammonia, methylamine, and 4-nitroimidazol, respectively, gave substituted 4-amino-3,5-dinitropyridine derivatives. Meanwhile, its azide derivative underwent a ring closure conversion into 7-amino-6-nitro-[1,2,5]oxadiazolo[3,4-b]- pyridine-1-oxide. It is of significance that all of the nucleophilic substitution reactions were carried out under mild conditions. 相似文献
15.
Raul Aguayo Felipe Arias Alvaro Cañete Carolina Zuñiga Enrique A. Castro Paulina Pavez José G. Santos 《国际化学动力学杂志》2013,45(3):202-211
The reactions of the title compounds with phenoxides, secondary alicyclic (SA) amines, and pyridines, in 44 wt% ethanol–water, at 25°C and an ionic strength of 0.2 M, were subjected to kinetic and product studies. From analytical techniques (HPLC and NMR), two pathways were detected (nucleophilic attack at the phosphoryl center and at the C‐1 aromatic carbon) for the reactions of all the nucleophiles with the phosphate ( 2 ) and for the pyridinolysis of the thionophosphate ( 1 ). Only aromatic nucleophilic substitution was found for the reactions of 1 with phenoxides and SA amines. For the dual reactions, the nucleophilic rate constants (kN) were separated in two terms: $k_{\rm N}^{\rm P}$ and $k_{\rm N}^{{\rm Ar}}$, which are the rate constants for the corresponding electrophilic centers. The absence of a break in the Brønsted‐type plots for the attack at P is consistent with concerted mechanisms. The Brønsted slopes, βAr 0.32–0.71, for the attack at the aromatic C‐1, are in agreement with stepwise mechanisms where formation of a Meisenheimer complex is the rate‐determining step. © 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 202–211, 2013 相似文献
16.
Dipl.‐Chem. Tanja Kanzian Dr. Simona Nicolini Dr. Lucia De Crescentini Prof. Dr. Orazio A. Attanasi Dr. Armin R. Ofial Prof. Dr. Herbert Mayr 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):12008-12016
The kinetics of the reactions of 1,2‐diaza‐1,3‐dienes 1 with acceptor‐substituted carbanions 2 have been studied at 20 °C. The reactions follow a second‐order rate law, and can be described by the linear free energy relationship log k(20 °C)=s(N+E) [Eq. (1)]. With Equation (1) and the known nucleophile‐specific parameters N and s for the carbanions, the electrophilicity parameters E of the 1,2‐diaza‐1,3‐dienes 1 were determined. With E parameters in the range of ?13.3 to ?15.4, the electrophilic reactivities of 1 a–d are comparable to those of benzylidenemalononitriles, 2‐benzylideneindan‐1,3‐diones, and benzylidenebarbituric acids. The experimental second‐order rate constants for the reactions of 1 a – d with amines 3 and triarylphosphines 4 agreed with those calculated from E, N, and s, indicating the applicability of the linear free energy relationship [Eq. (1)] for predicting potential nucleophilic reaction partners of 1,2‐diaza‐1,3‐dienes 1 . Enamines 5 react up to 102 to 103 times faster with compounds 1 than predicted by Equation (1), indicating a change of mechanism, which becomes obvious in the reactions of 1 with enol ethers. 相似文献
17.
Agnieszka Majchrzak Grzegorz Mlosto Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2006,89(5):1042-1061
The reactions of 3‐chloro‐3‐(chlorosulfanyl)‐2,2,4,4‐tetramethylcyclobutan‐1‐one ( 2 ) with N, O, S, and P nucleophiles occur by substitution of Cl at the S‐atom. Whereas, in the cases of secondary amines, alkanols, phenols, thiols, thiophenols, and di‐ and trialkyl phosphates, the initially formed substitution products were obtained, the corresponding products with allyl and propargyl alcohols undergo a [2,3]‐sigmatropic rearrangement to give allyl and allenyl sulfoxides, respectively. Analogous substitution reactions were observed when 3‐chloro‐3‐(chlorodisulfanyl)‐2,2,4,4‐tetramethylcyclobutan‐1‐one ( 3 ) was treated with N, O, and S nucleophiles. The reaction of 3 with Et3P led to an unexpected product via cleavage of the S? S bond (cf. Scheme 13). In the reactions of 2 with primary amines and H2O, the substitution products react further via elimination of HCl to yield the corresponding thiocarbonyl S‐imides and the thiocarbonyl S‐oxide, respectively. Whereas the latter could be isolated, the former were not stable but could be intercepted by MeOH (Scheme 4) or adamantanethione (Scheme 5). The structures of some of the substitution products were established by X‐ray crystallography. 相似文献
18.
Grzegorz Mlostoń Małgorzata Celeda Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2009,92(8):1520-1537
The three‐component reactions of 1‐azabicyclo[1.1.0]butanes 1 , dicyanofumarates (E)‐ 5 , and MeOH or morpholine yielded azetidine enamines 8 and 9 with the cis‐orientation of the ester groups at the C?C bond ((E)‐configuration; Schemes 3 and 4). The structures of 8a and 9d were confirmed by X‐ray crystallography. The formation of the products is explained via the nucleophilic addition of 1 onto (E)‐ 5 , leading to a zwitterion of type 7 (Scheme 2), which is subsequently trapped by MeOH or morpholine ( 10a ), followed by elimination of HCN. Similarly, two‐component reactions between secondary amines 10a – 10c and (E)‐ 5 gave products 12 with an (E)‐enamine structure and (Z)‐oriented ester groups. On the other hand, two‐component reactions involving primary amines 10d – 10f or NH3 led to the formation of the corresponding (Z)‐enamines, in which the (E)‐orientation of ester groups was established. 相似文献
19.
Jonathon E. Beves Edwin C. Constable Catherine E. Housecroft Markus Neuburger Silvia Schaffner Jennifer A. Zampese 《Helvetica chimica acta》2009,92(11):2214-2226
The syntheses of the five 2,2′: 6′,2″‐terpyridine (tpy) ligands 5 – 9 functionalized in the 4′‐position with a hydrazone substituent RR′C?N? NH (R=R′=Me; R=H, R′=4‐BrC6H4, 4‐O2NC6H4, 4‐MeOC6H4, or 3,5‐(MeO)2C6H3) are described. Protonation of the tpy domain of the ligands is facile. Solution behaviour has been studied by NMR and electronic spectroscopies. Representative structural data are presented for neutral and monoprotonated ligands, and illustrate that H‐bonding involving the formal amine NH unit is a dominant structural motif in all cases. 相似文献
20.
4‐Ethoxycarbonyl‐5‐phenyl‐2,3‐dihydrofuran‐2,3‐dione 1 reacts with aldehydes via the acylketene intermediate 2 giving the 1,3‐dioxin‐4‐ones 3a‐e and the 1,4‐bis(5‐ethoxycarbonyl‐4‐oxo‐6‐phenyl‐4H‐1,3‐dioxin‐2‐yl)benzene 4 , and a one step reaction between dibenzoylmethane and oxalylchloride gave 3,5‐dibenzoyl‐2,6‐diphenyl‐4‐pyrone 7 . The reaction of 1 with dibenzoylmethane, a dicarbonyl compound, provided ethyl 3‐benzoyl‐4‐oxo‐2,6‐diphenylpyran‐5‐carboxylate derivative 9 . Compound 9 was converted into the corresponding ethyl 3‐benzoyl‐4‐hydroxy‐2,6‐diphenylpyridine‐5‐carboxylate derivative 10 via its reaction with ammonium hydroxyde solution in 1 ‐butanol. 相似文献