- One-Pot Synthesis of Enantioenriched β-Amino Secondary Amides via an Enantioselective [4+2] Cycloaddition Reaction of Vinyl Azides with N-Acyl Imines Catalyzed by a Chiral Br?nsted Acid
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A catalytic enantioselective synthesis of β-amino secondary amides was achieved using vinyl azides as the enamine-type nucleophile and chiral N-Tf phosphoramide as the chiral Br?nsted acid catalyst through a five-step sequential transformation in one pot.
- Chiba, Shunsuke,Kaga, Atsushi,Kikuchi, Jun,Nakanishi, Taishi,Terada, Masahiro
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- A convenient one-pot approach to Paclitaxel (Taxol) side chain via 1,3-dipolar cycloaddition of carbonyl ylides and N-benzoylbenzyl imines
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An efficient cascade approach to α-hydroxy-β-amino acid derivatives is reported, which goes through a 1,3-dipolar cycloaddition of carbonyl ylides and N-benzoylbenzyl imines and followed by hydrolysis under acidic conditions. This is the first example of using N-benzoylbenzyl imine as dipolarophile for 1,3-dipolar cycloaddition with carbonyl ylide, which provides a direct and convenient access for the one-pot synthesis of paclitaxel side chain and its derivatives.
- Sheng, Jiajun,Chang, Huan,Qian, Yu,Ma, Mingliang,Hu, Wenhao
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p. 2141 - 2144
(2018/05/05)
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- A new reactivity mode for the diazo group: Diastereoselective 1,3-aminoalkylation reaction of β-amino-α-diazoesters to give triazolines
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A novel mode of reactivity for the diazo group, the 1,3-addition of a nucleophile and an electrophile to the diazo group, has been realized in the intramolecular aminoalkylation of β-amino-α-diazoesters to form tetrasubstituted 1,2,3-triazolines. The reaction exhibited a broad scope, good functional group tolerance, and excellent diastereoselectivity. In addition, a new Au-catalyzed intramolecular transannulation reaction of the obtained propargyl triazolines to give pyrroles has been discovered.
- Kuznetsov, Alexey,Gulevich, Anton V.,Wink, Donald J.,Gevorgyan, Vladimir
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p. 9021 - 9025
(2014/09/29)
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- Asymmetric synthesis of maraviroc (UK-427,857)
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The asymmetric synthesis of Maraviroc (UK-427,857), a chemochine receptor 5 (CCR-5) receptor antagonist, based on an expeditious organocatalytic enantioselective assembly of the chiral βamino aldehyde key fragment is presented. The reactions were performed on a gram-scale and allow for the rapid construction of new Maraviroc analogues.
- Zhao, Gui-Ling,Lin, Shuangzheng,Korotvicka, Ales,Deiana, Luca,Kullberg, Martin,Cordova, Armando
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supporting information; experimental part
p. 2291 - 2298
(2010/12/20)
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- N-Alkylation of carbamates and amides with alcohols catalyzed by a Cp*Ir complex
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New atom-economical catalytic systems consisting of [Cp*IrCl2]2/NaOAc (Cp*=pentamethylcyclopentadienyl) for the N-alkylation of carbamates and amides using alcohols as alkylating agents under solvent-free conditions have been developed. For example, the reaction of n-butyl carbamate with benzyl alcohol in the presence of [Cp*IrCl2]2 (5.0 mol % Ir) and NaOAc (5.0 mol %) at 130 °C under the absence of solvent gives n-butyl N-benzylcarbamate in the yield of 94%. The present catalytic system is applicable to not only carbamates but also amides, and only harmless water is produced as co-product.
- Fujita, Ken-ichi,Komatsubara, Atsuo,Yamaguchi, Ryohei
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experimental part
p. 3624 - 3628
(2009/09/06)
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- Modular synthesis of tetrasubstituted imidazoles and trisubstituted oxazoles by aldimine cross-coupling
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A study was conducted to demonstrate the synthesis of tetrasubstituted imidazoles and trisubstituted oxazoles by aldimine cross-coupling reaction. The method involved 1,2-addition of easily available deprotonated N-monosubstituted α-aminotitriles to aldim
- Kison, Coralie,Opatz, Till
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body text
p. 843 - 845
(2009/06/28)
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- Pd0/SnII promoted Barbier-type allylation and crotylation of sulfonimines
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A one-pot Barbier protocol is described for the facile formation of homoallyl sulfonamides from sulfonimines and allyl or crotyl bromide in the presence of SnCl2, and catalytic Pd2(dba)3·CHCl3 at room temperature.
- Roy, Ujjal Kanti,Roy, Sujit
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p. 7177 - 7180
(2008/03/11)
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- Metal catalyzed multicomponent syntheses of secondary propargylamides and oxazoles from silylimines, acid chlorides, and alkynes
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Copper(I) and zinc(II) catalyzed routes to construct secondary propargylamides in one-pot procedures from aldehydes, LiN(TMS)2, acid chlorides, and alkynes are described. This reaction has been subsequently used to provide a one-pot synthesis o
- Black, Daniel A.,Arndtsen, Bruce A.
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p. 11317 - 11321
(2007/10/03)
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- OXIDATION OF N-BENZYLIDENEBENZYLAMINE BY OXYGEN THROUGH THE FORMATION OF A CARBANION
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A study was carried out on the oxidation of the methylene group of N-benzylidenebenzylamine through the formation of a carbanion.The conditions were found for a combined oxidation-reduction process using KOH, O2, solvent, dibenzo-18-crown-6 and NaBH4, in which the oxidation is shifted toward the formation of a hydroxy compound, namely, N-benzylidene-2-hydroxybenzylamine.Oxidation in this system is a convenient preparative method for introducing a hydroxyl group into "acidic" CH bonds.
- Grigoryan, G. S.,Tovmasyan, V. S.,Malkhasyan, A. Ts.,Martirosyan, G. T.,Beletskaya, I. P.
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p. 1043 - 1046
(2007/10/02)
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- Photochemistry of Aminoketones. V. - Diastereoselective Synthesis of 3-Aryl-azetidin-3-ols via Photocyclization of Aryl-α-amidoalkyl-ketones
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N-Acyl-azetidin-3-ols 3 and 4 are formed by diastereoselective cyclization of n,?*-excited N-benzyl-N-phenacyl-amides 1 and 2 in ether solution.Dependent on the nature of the p- and α-substituents of the phenacyl part and especially of the N-acylgroups in the amides 1 and 2 competing reactions occur, particularly the NORRISH II cleavage and an oxydative cleavage of the intermediate hydroxybiradicals A.N-Acylgroups with low energy barrier ΔG(excit.) of internal rotation favour the diastereoselective photocyclization by intramolecular interaction between the amide oxygen atom and the n,?*-CO-group in 1*, 2* and the OH group in the biradicals A, respectively.An intramolecular hydrogen bonding enables the N-tosyl-azetidinols 3 to rearrange to the N-tosylaminomethyl-benzhydryl-ketones 6 by 1-sensitized photoreaction.
- Fuhrmann, J.,Haupt, M.,Henning, H.-G.
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p. 177 - 186
(2007/10/02)
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- Thermal and Photochemical Behaviour of N-(α-Morpholinobenzyl)-benzamide and N-(α-Methoxybenzyl)benzamide
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The thermal fragmentation of the title compounds produces benzamide (6), benzaldehyde (7), and N,N'-benzylidenebisbenzamide (8); in contrast the photochemical reaction gives benzylbenzamide (9) and meso- and (+/-)-1-modifications of N,N'-dibenzoyl-1,2-diphenyl-1,2-diaminoethane (10).Evidence is presented which shows that the formation of the various reaction products starts from the N-benzylidenebenzamide (5).
- Chiacchio, Ugo,Corsaro, Antonino,Compagnini, Anna,Purrello, Giovanni
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p. 671 - 674
(2007/10/02)
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