- A general method for the preparation of chiral TREN derivatives
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A general procedure for the preparation of C3-symmetric TREN derivatives with backbone chirality has been developed. Stereo- and regioselective ring opening by ammonia of (S)-N-tosyl-2-isopropylaziridine, obtained starting from either the corre
- Pei, Yuxin,Brade, Katja,Brule, Emilie,Hagberg, Lars,Lake, Fredrik,Moberg, Christina
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- Synthesis and hetero-Diels-Alder reactions of enantiomerically pure dihydro-1: H -azepines
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Thermolysis of enantiomerically pure 3-substituted 7,7-dihalo-2-azabicyclo[4.1.0]heptanes in the presence of K2CO3 gives in good yields 2-alkyl-6-halo-1-tosyl-2,3-dihydro-1H-azepines. These undergo highly stereoselective [4+2] cycloaddition reactions with heterodienophiles and arylation/alkenylation under Suzuki conditions.
- Craig, Donald,Spreadbury, Samuel R. J.,White, Andrew J. P.
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p. 9803 - 9806
(2020/09/16)
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- Synthesis of Enantiopure PZM21: A Biased Agonist of the Mu-Opioid Receptor
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PZM21 (1) was recently reported as a biased agonist of the mu-opioid receptor (MOR) with improved antinociceptive effects and reduced side effects compared with traditional opioid-based analgesics. The original synthesis of PZM21 with the desired (S,S) configuration required the separation of a diastereomeric mixture in the final step by using chiral HPLC. A concise synthesis of 1 has now been developed in the enantiomeric pure form starting with commercially available l-alanine and proceeding via a chiral aziridine as a key intermediate. The final product was obtained as the (S,S) diastereomer in seven steps in 22.5 % yield from l-alanine. This synthetic strategy could be readily applied to the development of PZM21 analogues at the thiophenyl position.
- Perrey, David,Zhang, Dehui,Nguyen, Thuy,Carroll, F. Ivy,Ko, Mei-Chuan,Zhang, Yanan
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p. 4006 - 4012
(2018/07/30)
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- Modular One-Step Three-Component Synthesis of Tetrahydroisoquinolines Using a Catellani Strategy
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Reported is a modular one-step three-component synthesis of tetrahydroisoquinolines using a Catellani strategy. This process exploits aziridines as the alkylating reagents, through palladium/norbornene cooperative catalysis, to enable a Catellani/Heck/aza-Michael addition cascade. This mild, chemoselective, and scalable protocol has broad substrate scope (43 examples, up to 90 % yield). The most striking feature of this protocol is the excellent regioselectivity and diastereoselectivity observed for 2-alkyl- and 2-aryl-substituted aziridines to access 1,3-cis-substituted and 1,4-cis-substituted tetrahydroisoquinolines, respectively. Moreover, this is a versatile process with high step and atom economy.
- Qian, Guangyin,Bai, Miao,Gao, Shijun,Chen, Han,Zhou, Siwei,Cheng, Hong-Gang,Yan, Wei,Zhou, Qianghui
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p. 10980 - 10984
(2018/07/30)
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- Cu-Catalyzed [3 + 3] Cycloaddition of Isocyanoacetates with Aziridines and Stereoselective Access to α,γ-Diamino Acids
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We report herein an efficient Cu-catalyzed formal [3 + 3] cycloaddition of isocyanoacetates with readily available aziridines of different substitution patterns, which provides a practical access to valuable 1,4,5,6-tetrahydropyrimidine derivatives. In pa
- Kok, Germaine Pui Yann,Yang, Hui,Wong, Ming Wah,Zhao, Yu
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supporting information
p. 5112 - 5115
(2018/09/12)
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- Enantiodivergent Synthesis of (+)- and (?)-Pyrrolidine 197B: Synthesis of trans-2,5-Disubstituted Pyrrolidines by Intramolecular Hydroamination
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A highly efficient, diastereoselective, iron(III)-catalyzed intramolecular hydroamination/cyclization reaction involving α-substituted amino alkenes is described. Thus, enantiopure trans-2,5-disubstituted pyrrolidines and trans-5-substituted proline derivatives were synthesized by means of a combination of enantiopure starting materials, easily available from l-α-amino acids, with sustainable metal catalysts such as iron(III) salts. The scope of this methodology is highlighted in an enantiodivergent approach to the synthesis of both (+)- and (?)-pyrrolidine 197B alkaloids from l-glutamic acid. In addition, a computational study was carried out to gain insight into the complete diastereoselectivity of the transformation.
- Pérez, Sixto J.,Purino, Martín A.,Cruz, Daniel A.,López-Soria, Juan M.,Carballo, Rubén M.,Ramírez, Miguel A.,Fernández, Israel,Martín, Víctor S.,Padrón, Juan I.
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supporting information
p. 15529 - 15535
(2016/10/13)
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- A Modular Synthesis of Multidentate S-, N- and O-Containing Meta- and Paracyclophanes
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The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from (R)- or (S)-alanine, a representative amino acid. The facile, regioselective, nucleophilic ring opening of aziridines by dithiols enabled the synthesis of thioether-based linkers which on subsequent alkylation provided access to optically pure macrocycles. A modular approach to macrocyclic assembly has enabled the synthesis of a library of macrocycles possessing multiple donor sites where chirality was readily introduced from (S)-alanine. Key to this approach was the facile, regioselective, nucleophilic ring opening of aziridines by dithiols followed by macrocylisation under conditions of high dilution.
- Rasheed, Omer K.,Bailey, Patrick D.,Lawrence, Amy,Quayle, Peter,Raftery, James
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supporting information
p. 6988 - 6993
(2015/11/16)
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- Fluoroalkanosulfonyl fluorides-mediated cyclodehydration of β-hydroxy sulfonamides and β-hydroxy thioamides to the corresponding aziridines and thiazolines
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An efficient method for the fluoroalkanosulfonyl fluoride-induced cyclodehydration of β-hydroxy sulfonamides and β-hydroxy thioamides to the corresponding aziridines and thiazolines is reported. Mild reaction conditions, operational simplicity, and high y
- Yan, Zhaohua,Guan, Chengbo,Yu, Zhangxin,Tian, Weisheng
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supporting information
p. 5788 - 5790
(2013/10/01)
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- An efficient synthetic approach for N-C bond formation from (S)-amino acids: An easy access to cis-2,5-disubstituted chiral piperazines
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An efficient synthetic strategy is described for the construction of amino acids derived enantiomerically pure cis-2,5-disubstituted chiral piperazines. Cu-catalyzed spontaneous regioselective ring opening and ring closing of non-activated N-tosyl aziridines as well as Pd-mediated N-C bond formation from N-tosyl halogenated amino-derivatives are the key steps for accessing disubstituted piperazines.
- Manna, Sudipta Kumar,Panda, Gautam
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p. 18332 - 18338
(2013/10/21)
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- Regioselective ring-opening of amino acid-derived chiral aziridines: An easy access to cis-2,5-disubstituted chiral piperazines
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An efficient four-step synthetic strategy for cis-2,5-disubstituted chiral piperazines derived from amino-acid-based aziridines is described. The key steps in this strategy are the highly regioselective boron trifluoride diethyl etherate (BF3·OEt2)-mediated ring-opening of less-reactive N-Ts chiral aziridines by α-amino acid methyl ester hydrochloride followed by Mitsunobu cyclization. This protocol has been used in an attempt to construct the piperazine core framework of natural product (+)-piperazinomycin. The pied piperazines: A four-step efficient synthetic strategy for cis-2,5-disubstituted chiral piperazines derived from amino acid-based aziridines is described. The key reaction steps are the highly regioselective BF3·OEt2 mediated ring-opening of less-reactive N-Ts chiral aziridines by α-amino acid methyl ester hydrochlorides, followed by a Mitsunobu cyclization. This protocol has been used in an attempt to construct the piperazine core framework of natural product (+)-piperazinomycin. Copyright
- Samanta, Krishnananda,Panda, Gautam
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supporting information; experimental part
p. 189 - 197
(2011/10/08)
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- One-pot and microwave-assisted synthesis of N-sulfonylaziridines
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A novel and efficient microwave-assisted one-step reaction was developed to synthesize chiral N-sulfonylaziridines by the reaction of different chiral amino alcohols and sulfonic chlorides. The newly developed microwave synthetic method has the advantage of reducing the reaction time from 24 to 0.5 h with improved yields (84-93%) and minimizing by-products.
- Xu, Hao,Tian, Hua,Zheng, Liangyu,Liu, Qingwen,Wang, Li,Zhang, Suoqin
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experimental part
p. 2873 - 2875
(2011/06/21)
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- NOVEL B1 BRADYKININ RECEPTOR ANTAGONISTS
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The invention encompasses novel compounds of a formula I and pharmaceutically acceptable derivatives thereof, pharmaceutical compositions and methods for treatment of diseases mediated by B1 bradykinin receptor.
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Page/Page column 51-52
(2010/11/08)
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- Bifurcated, modular syntheses of chiral annulet triazacyclononanes.
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Three chiral 2,6-disubstituted tri-N-methyl azamacrocycles have been prepared by modular methods. These macrocycles were accessed from three chiral 1,4,7-triazaheptanes intermediates that were prepared by two independent routes. The first of these routes
- Argouarch, Gilles,Stones, Graham,Gibson, Colin L,Kennedy, Alan R,Sherrington, David C
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p. 4408 - 4417
(2007/10/03)
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- The synthesis of chiral annulet 1,4,7-triazacyclononanes
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Novel and flexible routes for the synthesis of chiral ring annulet 2,6-disubstituted 1,4,7-trimethyl-1,4,7-triazamacrocycles are described. Efficient macrocyclisations were realised provided that chiral analogues of N,N-bis-[2-(toluene-sulfonylamino)ethyl]-toluene-4-sulfonamide were used as the nucleophilic components. Complexes prepared, in situ, from these 2,6-disubstituted 1,4,7-trimethyl-1,4,7-triazamacrocycles and manganese(II) catalysed the asymmetric epoxidation of styrene with hydrogen peroxide.
- Argouarch, Gilles,Gibson, Colin L,Stones, Graham,Sherrington, David C
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p. 3795 - 3798
(2007/10/03)
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- Macrocyclic polyamine lactones and derivatives thereof and their use as arthropod repellents
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The present invention describes an isolated macrocycle having the formula: where d is an integer from 0 to about 100; A, B, and each D are the same or different and are selected from the group consisting of each R1is the same or different and is a bivalent alkylene moiety; each R2is the same or different and is a bivalent alkylene moiety; and each R3is the same or different and is selected from the group consisting of a hydrogen atom and an alkyl moiety. Methods for producing these macrocycles are also described. The macrocycles of the present invention can be used as arthropod repellents.
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Page column 27
(2010/02/05)
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- Short and efficient synthesis of optically active N-tosyl aziridines from 2-amino alcohols
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Two alternative and complementary one-pot procedures for the direct transformation of 2-amino alcohols to N-tosyl aziridines are presented. The unsubstituted parent compound and its less hindered homologues can be obtained in high yields by tosylation and
- Bieber, Lothar W.,De Araujo, Maria C. F.
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p. 902 - 906
(2007/10/03)
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- A concise, modular synthesis of chiral peraza-macrocycles using chiral aziridines
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(equation presented) Novel chiral peraza-macrocycles were synthesized from chiral aziridines as a common building block. Efficient syntheses of chiral [26]-N6, [12]-N4, [9]-N3, and [14]-N4 systems were accomplis
- Kim, B. Moon,So, Soon Mog,Choi, Hye Jin
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p. 949 - 952
(2007/10/03)
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- A new convenient approach to chiral β-aryl(heteroaryl)alkylamines
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Chiral β-aryl(heteroaryl)alkylamines have been prepared from N-tosyl alkylaziridines via regiospecific nucleophilic ring opening and subsequent desulfonylation in good to excellent yields. The corresponding aziridines are easily obtained from commercially available (S)-α-amino acids, so this method is the first effective route to asymmetric β-aryl(heteroaryl)alkylamines.
- Nenajdenko, Valentine G,Karpov, Alexei S,Balenkova, Elizabeth S
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p. 2517 - 2527
(2007/10/03)
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- C3-Symmetric tripodal tetra-amines - preparation from chiral amino alcohols via aziridines
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Enantiopure N-sulfonylaziridines, conveniently obtained from readily available enantiopure amino alcohols, undergo smooth ring opening reactions using ammonia as a nucleophile to yield tripodal tetradentate C3-symmetric amines. N-alkylation and
- Cernerud, Magnus,Adolfsson, Hans,Moberg, Christina
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p. 2655 - 2662
(2007/10/03)
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- SYNTHESIS OF SUBSTITUTED TETRAHYDROPYRIDINES BY CYCLIZATIONS OF SILICON-CONTAINING IMINIUM IONS
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Trans-2,6-disubstituted-1,2,5,6-tetrahydropyridines are formed stereoselectively from the cyclization of silicon-containing iminium cations 5 if the nitrogen substituents R1 is an alkyl group.In contrast, cyclization of the corresponding NH or N-acyl iminium ions occurs in a stereorandom fashion.Nonracemic tetrahydropyridines cannot be prepared in this way, since both iminium ion and N-acyliminium ion intermediates racemize prior to cyclization.
- Daub, G. William,Heerding, Dirk A.,Overman, Larry E.
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p. 3919 - 3930
(2007/10/02)
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