- Selective preparation of (Z)- and (E)-prop-1-enylamides from N-allylbenzamides
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A series of para-substituted N-allylbenzamides was submitted to isomerization under basic conditions. With LDA at -78°C, the corresponding (E)-N-(prop-1-enyl)benzamide was the major product. With n-butyllithium and the mixture warmed to 0°C, the (Z)-isomer was essentially furnished.
- Ribéreau, Pierre,Delamare, Madeleine,Célanire, Sylvain,Quéguiner, Guy
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Read Online
- XtalFluor-E mediated proto-functionalization of: N -vinyl amides: Access to N -acetyl N, O -acetals
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XtalFluor-E has been extensively used in a broad range of reactions in the past few years. Here we report its use with protic nucleophiles in a catalytic manner for the in situ generation of protons that lead to the proto-functionalization of activated ol
- Yi,Gholami,Morrow,Borhan
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p. 9570 - 9574
(2017/11/30)
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- A convenient synthesis of N-vinyl enamides via the lithiation and ring-opening reaction of 2-phenyl-2-oxazolines
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A simple and efficient synthesis of N-vinyl enamides via the lithiation and ring-opening reaction of 2-phenyl-2-oxazolines with lithium diisopropylamide at room temperature has been developed. This method is especially suitable for the synthesis of multif
- Xu, Yi,Liu, Xiao-Yu,Wang, Zi-Qi,Tang, Liang-Fu
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p. 1788 - 1791
(2017/04/13)
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- Structure-Dependent Nickel-Catalysed Transposition of N -Allylamides to E- or Z-Enamides
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The nickel-catalysed transposition of a carbon-carbon double bond of N-allyl and N-homoallyl amides is described. While the transposition of acyclic amides gave very high Z-selectivity of the enamides, corresponding cyclic N-allyl amides led exclusively t
- Weber, Felicia,Steinlandt, Philipp S.,Ballmann, Monika,Hilt, Gerhard
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p. 440 - 450
(2016/12/24)
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- Pd-Boron-Catalyzed One Carbon Isomerization of Olefins: Water Assisted Process at Room Temperature
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A palladium-boronate/borane-system -catalyzed isomerization of olefins has been uncovered. An efficient catalytic combination of [Pd(OAc)2]3-boronate-PCy3-enabled olefin isomerization at 80 °C has been investigated. Addition of water to the reaction showed a remarkable improvement and the isomerization occurred at ambient temperature. These catalytic systems function efficiently for the isomerization of functionalized as well as unfunctionalized olefins. The catalytic conditions demonstrate the involvement of both nonhydride and metal-hydride medium and can be switchable with water as an additive.
- Ojha, Devi Prasan,Gadde, Karthik,Prabhu, Kandikere Ramaiah
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p. 4859 - 4865
(2017/05/12)
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- Nickel-Catalyzed Synthesis of Enamides and Enecarbamates via Isomerization of Allylamides and Allylcarbamates
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A single-component, air-stable nickel precatalyst can catalyze the isomerization of allylamides for the synthesis of enamides. The scope of the reaction encompasses various substituted allylamides and allylcarbamates as well as homoallylamides. The reaction can be performed on a multigram-scale without specialized glove-box equipment or Schlenk techniques.
- Halli, Juliette,Kramer, Philipp,Bechthold, Maren,Manolikakes, Georg
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supporting information
p. 3321 - 3324
(2015/11/03)
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- Relay catalysis by a metal-complex/bronsted acid binary system in a tandem isomerization/carbon-carbon bond forming sequence
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A one-pot tandem isomerization/carbon-carbon bond forming sequence catalyzed by a ruthenium complex/Bronsted acid binary system is demonstrated. The method enables the use of readily available allylamides to deliver reactive imines under relay catalysis using a binary catalytic system. Subsequent Bronsted acid catalyzed carbon-carbon bond forming reactions of the generated imines with nucleophilic components afforded Friedel-Crafts and Mannich products in good yields. Copyright
- Sorimachi, Keiichi,Terada, Masahiro
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supporting information; experimental part
p. 14452 - 14453
(2009/02/08)
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- Reactions of N-acylaziridines with sodium metal and sodium naphthalenide. Elimination of olefines
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Reactions of N-acylaziridines 1a-g (N-benzoyl except 1d) with sodium or naphthalenide N.- in THF provide a variety of products that usually arise via the aziridino ketyls 2. Homolytic ring opening of 2 generates the amidatoalkyl radicals 3. Only with a very short reaction time were small amounts of benzil or benzoylnaphthalenes obtained indicating a reversible trapping of 2 by dimerization or coupling with N.-. Homolysis of 2 produced always the more stable 3 apart from reactions of monomethylaziridines 1c,d where the primary radical i-3c,d is kinetically favoured. The amides R1CONHCHR4CHR2R3 (9, isopropylamides i-9c,d from 1c,d) were usually the main products. 9 arise from 3 either by H atom abstraction from THF (probably in sodium metal runs) or by reduction of 3 to carbanions 5 that abstract a proton from THF (N.- runs). Addition of 5a (R2-4 = H) to 1a gives finally the ketone 8a. Self reaction of primary radical 3a is dimerization. Self reaction of tertiary or secondary radicals is disproportionation when an allylamide arises. This isomerizes to an enamide unless it is conjugated. R2R3C=CHR4 and R1CONH2 arise (probably) always. The mechanism, possibly a cyclic process of anion 6, is not clear. Johann Ambrosius Barth 1996.
- Lin, Pen-Yuan,Bellos, Konstantinos,Werry, Juergen,Assithianakis, Petros,Weiss, Rainer,Mall, Thomas,Bentz, Gunther,Stamm, Helmut
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p. 270 - 278
(2007/10/03)
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- Silylamines in Organic Synthesis. Reactivity of N,N-Bis(silyl) Enamines toward Electrophiles. A Route to Substituted 2-Aza-1,3-butadienes and Pyridines
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N,N-Bis(silyl) enamines appeared to be weak nucleophilic reagents and exhibited a very low reactivity toward electrophiles.However, in the presence of a nucleophilic catalyst, nucleophilic activation of the silicon-nitrogen bond was observed.Under fluoride ion catalysis (TBAF or CsF), N,N-bis(silyl) enamines reacted with carbonyl compounds to give substituted 2-aza-1,3-butadienes.Good yields were obtained in reactions with aromatic aldehydes or ketones.In the case of aliphatic carbonyl compounds, 2-aza 1,3-dienes were only formed in moderate yields.Interestingly, enamidines were easily obtained in high yields upon reactions of dimethylformamide in the presence of MeONa as catalyst.The reaction of aromatic α,β-unsaturated ketones gave 2-aza 1,3,5-trienes, which were not isolated but underwent an intramolecular cycloaddition reaction with regioselective formation of substituted 2,4-diarylpyridines.
- Corriu, Robert J. P.,Moreau, Joel J. E.,Pataud-Sat, Magali
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p. 2878 - 2884
(2007/10/02)
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- Rhodium-catalyzed coupling of N-allylamides of organic acids
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N-Allylamides of organic acids have been shown to couple with unsaturated diamides under catalysis by a rhodium(I) complex.The synthesis is regioselective and moderately stereoselective, the Z diamide being obtained predominantly.A metallacyclic intermediate is suggested.
- Chiusoli, Gian Paolo,Costa, Mirco,Pivetti, Fausto
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p. 385 - 390
(2007/10/02)
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- ACTIVATION OF SILICON-HYDROGEN, SILICON-OXYGEN, SILICON-NITROGEN BONDS IN HETEROGENEOUS PHASE SOME NEW METHODS IN ORGANIC SYNTHESIS
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Anionic activation of Si-H, Si-O and Si-N bonds by fluoride ions under heterogeneous conditions is reported: Si-H activated by KF or CsF is a powerful and selective reducing reagent; the carbonyl group of aldehydes, ketones or esters can be reduced without reduction of other functional groups (C=C, NO2, Br, amido).Furthermore, selective reductions of aldehydes in the presence of ketones and ketones in the presence of carboxylic esters are also possible.CsF in the presence of Si(OR)4 is found to be very efficient in promoting Michael additions of monoketones andarylacetonitriles on different kinds of Michael acceptors such as α, β unsaturated ketones, esters, nitriles and even amides.This constitutes an extension of Michael reaction since the addition occurs even with crowded ketones.N,N bis(silyl)enamines activated by fluoride ions react with carbonyl compounds and provide an interesting route to 2-aza-1,3 dienes.
- Corriu, R. J. P.,Perz, R.,Reye, C.
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p. 999 - 1010
(2007/10/02)
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- Flash Vacuum Thermolysis of Functionalized γ-Sultines
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The flash vacuum thermolysis (FVT) of the 4-benzamido γ-sultines 5a and 5b is shown to lead to a mixture of the N-allyl amide 6 and enamides 7 and 8, the allyl amide being the main product.This reaction involves a novel migration of the benzamido group, which is proposed to proceed as depicted in path c of Scheme IV.This proposed mechanism features heterolytic bond fission, accompanied by neighboring group participation.Support for this proposal has been found by flash vacuum thermolysis (FVT) of 5a-d2 (Scheme IV).
- Liskamp, Rob M. J.,Blom, Henk J.,Nivard, Rutger J. F.,Ottenheijm, Harry C. J.
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p. 2733 - 2736
(2007/10/02)
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- N,N-bis(silyl)enamines as protected primary vinylamines. Nucleophilic activation of the silicon-nitrogen bond.
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N,N-bis(silyl)enamines react with electrophiles in the presence of catalytic amounts of nucleophile.The reaction of carbonyl compounds catalyzed by fluoride ion provides an interesting route to 2-aza-1,3-dienes.The methoxide ion catalyzed reaction of N,N-dimethylformamide gives rise to enamidines.
- Corriu, Robert J. P.,Huynh, Vilam,Moreau, Joel J. E.,Pataud-Sat, Magali
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p. 3257 - 3260
(2007/10/02)
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- Thermolyse von Oxazolin-5-onen, XI. N-Acylimine und Enamide durch Gasphasenpyrolyse von 4-Alkyl-2-oxazoline-5-onen
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On gas phase thermolysis 4-alkyl-2-oxazolin-5-ones 1 undergo CO elimination to yield N-acylimines 2, which rearrange into more stable enamides 3 if α-hydrogens are present.N-Acylimines (e.g. 2a) may be isolated in cases where the rearrangement is prevented by a quarternary C-atom.The 4,4-dialkylsubstituted oxazolinone 1o yields mixtures of N-acylimine 2o and enamide 3o, the amount of the latter increasing at higher pyrolysis temperatures.
- Jendrzejewski, Stefan,Steglich, Wolfgang
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p. 1337 - 1342
(2007/10/02)
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