82259-09-4Relevant academic research and scientific papers
Synthesis of 5-Substituted 2-Pyrrolidinones by Coupling of Organozinc Reagents with Cyclic N-Acyliminium Ions
Hidalgo-Mercado, Yazmín I.,Olivo, Horacio F.,Romero-Ortega, Moisés,Santos-Sánchez, Zaira A.,Zaragoza-Galicia, Ivann
, p. 4650 - 4656 (2019/12/11)
A coupling reaction between cyclic N-acyliminium ions with organozinc reagents is described. The cyclic N-acyliminium ions, generated in situ from N-substituted-5-hydroxy-2-pyrrolidinones by treatment with boron trifluoride-diethyl ether complex or titani
Synthesis of γ-Lactams by Mild, o-Benzoquinone-Induced Oxidation of Pyrrolidines Containing Oxidation-Sensitive Functional Groups
Rong, Hao-Jie,Cheng, Yong-Feng,Liu, Fan-Fan,Ren, Shu-Jian,Qu, Jin
, p. 532 - 540 (2017/04/26)
The late-stage oxidation of substituted pyrrolidines offers good flexibility for the construction of γ-lactam libraries, and especially in recent years the methods for functionalization of pyrrolidine have been available. We reported a new strategy for oxidation of pyrrolidines to γ-lactams: reaction of pyrrolidine with an o-benzoquinone gives an N,O-acetal by direct oxidation of the α-C-H bond of the pyrrolidine ring, and then the N,O-acetal is further oxidized by the o-benzoquinone to the γ-lactam. Because the first oxidation occurs selectively at the α-C-H of the pyrrolidine ring, oxidation-sensitive functional groups (allyl-, vinyl-, hydroxyl-, and amino groups) on pyrrolidine ring are unaffected. The synthetic utility of this novel method was demonstrated by the facile syntheses of (S)-vigabatrin and two analogues.
A versatile enantioselective synthesis of azabicyclic ring systems: A concise total synthesis of (+)-grandisine D and unnatural analogues
Fadeyi, Olugbeminiyi O.,Senter, Timothy J.,Hahn, Kristopher N.,Lindsley, Craig W.
supporting information; experimental part, p. 5826 - 5831 (2012/06/29)
Closing in on azacines: We have developed a new six step approach for the rapid and enantioselective synthesis of indolizidine, pyrrolo[1,2-a]azepine, and pyrrolo[1,2-a]azocine azabicyclic systems and their respective lactam congeners, which are found in a host of natural products as well as pharmaceutical preparations. This protocol enables a concise enantioselective total synthesis of (+)-grandisine D in 16.4 % overall yield from commercial materials (see scheme). Copyright
Stereoselective conjugate addition of lactams to nitroalkenes and formal total synthesis of indolizidine 167B
Kamimura, Akio,Nagata, Yoshiaki,Kadowaki, Ayako,Uchida, Kosuke,Uno, Hidemitsu
, p. 11856 - 11861 (2008/03/13)
Optically active 5-substituted pyrrolidin-2-ones underwent conjugate addition to nitroalkenes to give the corresponding adducts in a diastereoselective manner. The presence of 18-crown-6 was crucial to achieve good stereoselective addition. Addition of 6-substituted piperidin-2-ones also gave the corresponding adduct in a stereoselective manner. The adduct was readily converted into a bicyclic lactam through intramolecular nitroaldol reaction, and the formal synthesis of indolizidine 167B was achieved.
Synthesis of alkaloid analogues from β-amino alcohols by β-fragmentation of primary alkoxyl radicals
Boto, Alicia,Hernandez, Dacil,Hernandez, Rosendo,Montoya, Adriana,Suarez, Ernesto
, p. 325 - 334 (2007/10/03)
The fragmentation of primary alkoxyl radicals is usually a minor process with respect to hydrogen abstraction and other competing reactions. However, when β-amino alcohols were used as substrates, the scission proceeded in good to excellent yields and no side reactions were observed. The fragmentation can be coupled with an allylation or alkylation reaction, to give alkaloid analogues and functionalized nitrogen heterocycles. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
ENANTIOPURE HETEROCYCLIC COMPOUND USEFUL FOR THE PREPARATION OF PEPTIDES WHICH CAN BE POTENTIALLY USED AS MEDICAMENTS
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Page/Page column 16, (2008/06/13)
Enantiopure heterocyclic compound Enantiopure heterocyclic compound of formula (I) in which J is chosen from C, N, O and S; Z is H or a group for protecting the amino functional group, R3 denotes H or an organic residue, m is 0, 1 or 2 and n is 0, 1 or 2, and in which the heterocycle is preferably substituted with at least one substituent other than CH2-COOR3.
Stereoselectivity in reactions of atropisomeric lactams and imides
Bennett, D. Jonathan,Blake, Alexander J.,Cooke, Paul A.,Godfrey, Christopher R.A.,Pickering, Paula L.,Simpkins, Nigel S.,Walker, Matthew D.,Wilson, Claire
, p. 4491 - 4511 (2007/10/03)
A range of reactions of cyclic lactam systems is described in which an atropisomeric C-N axis controls the stereochemical outcome of ring substitution or addition. In the case of enantiopure menthol adducts, substitution via N-acyliminium intermediates occurred with essentially complete control. However, the range of nucleophiles that participate in the reaction is very limited and at present the removal of the N-aryl substituent is problematic. A six-membered enamide is of moderate configurational stability and the axis exerts synthetically useful levels of control over enolate alkylations of the system. A novel Lewis acid mediated enamide arylation process was identified.
Synthesis of alkaloids from aminol derivatives by β-fragmentation of primary alkoxyl radicals
Boto, Alicia,Hernández, Rosendo,Montoya, Adriana,Suárez, Ernesto
, p. 1559 - 1563 (2007/10/03)
The fragmentation of primary alkoxyl radicals, often described as low yielding and plagued by side reactions, proceeded in good to excellent yields when aminol derivatives were used as substrates. Remarkably, no side reactions such as hydrogen abstraction
Expedient syntheses of indolizidines (-)-167B and (-)-209D
Kim, Guncheol,Lee, Eun-ju
, p. 2073 - 2076 (2007/10/03)
Indolizidine alkaloids (-)-167B and (-)-209D were synthesized via an expedient route using hydroacylation and amination.
Tandem radical decarboxylation-oxidation of amino acids: A mild and efficient method for the generation of N-acyliminium ions and their nucleophilic trapping
Boto, Alicia,Hernandez, Rosendo,Suarez, Ernesto
, p. 4930 - 4937 (2007/10/03)
A convenient methodology for the synthesis of 2-substituted pyrrolidines from α-amino acids is described. A number of cyclic and acyclic α-amino acid derivatives have been prepared in order to test the scope and diastereoselectivity of this method. These substrates were treated with iodosylbenzene or (diacetoxyiodo)benzene (DIB) and iodine in order to generate the corresponding carboxyl radical, which evolves by loss of carbon dioxide to produce a carbon radical which in turn undergoes oxidation to an N-acyliminium ion. This postulated intermediate could be trapped inter- or intramolecularly by oxygen, nitrogen and carbon nucleophiles. In the case of carbon nucleophiles, a Lewis acid is required for the concomitant carbon-carbon bond formation. High yields and modest diastereoselectivities were obtained. The present methodology was applied to the synthesis of ω-amino aldehydes or hemiaminals 8-14, 2-aminopyrrolidine derivative 15, aminolactone derivative 16, and azasugar analogues 17 and 18. When carbon nucleophiles were used, alkaloid precursors such as 2-allyl- or 2-alkylpyrrolidines 19-23 and 25 were obtained.
