Enantioselective synthesis of chiral α-alkynylated thiazolidones by tandem S-addition/acetalization of alkynyl imines

2020 ◽  
Vol 18 (16) ◽  
pp. 3117-3124
Author(s):  
Mei-Xin Wang ◽  
Juan Liu ◽  
Zhen Liu ◽  
Yingcheng Wang ◽  
Qi-Qiong Yang ◽  
...  

A SPINOL-CPA catalyzed asymmetric [2 + 3]-annulation of in situ generated alkynyl imines and 1,4-dithiane-2,5-diol has been developed to afford enantiopure α-alkynylated thiazolidones.

Synlett ◽  
2021 ◽  
Author(s):  
Dominik Albat ◽  
Jörg-Martin Neudörfl ◽  
Hans-Günther Schmalz

An exceedingly short and enantioselective synthesis of the antiepileptic drug (S)-levetiracetam was elaborated. As the chirogenic key step a Pd-catalyzed asymmetric N-allylation of methyl 4-aminobutyrate was achieved in the presence of only 1 mol% of a catalyst prepared in situ from [Pd(allyl)Cl]2 and the tartaric acid-derived C2-symmetric diphosphane ligand (S,S)-iPr-MediPhos).


2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Shengwei Wei ◽  
Bernhard Schmid ◽  
Fliur Z. Macaev ◽  
Serghei N. Curlat ◽  
Andrei V. Malkov ◽  
...  

Abstract The application of a convenient one-pot synthetic strategy, utilizing an in situ formed organocatalyst, to the enantioselective synthesis of anti-leukaemia agent (R)-convolutamydine A has been demonstrated.


Synthesis ◽  
2019 ◽  
Vol 51 (09) ◽  
pp. 1923-1934 ◽  
Author(s):  
Jean Rodriguez ◽  
Adrien Quintard

In order to circumvent reactivity or selectivity issues associated with the addition of enolates to electrophiles, chemists have devised innovative methods involving transient activating groups. One of these powerful methods consists of the use of activated ketones, such as α-nitroketones, β-dicarbonyl compounds or β-ketosulfones, with electrophiles possessing a latent hydroxy or amine function. In the presence of a suitable catalyst, an enantioselective addition to the electrophile is facilitated triggering a subsequent Claisen-type fragmentation resulting in an acyl transfer. This subsequent step unveils the desired mono-activated function while directly transferring the ketone, forming in situ on the other side an ester or an amide.1 Introduction2 Intramolecular Acyl Transfer with Acyclic Substrates2.1 Bifunctional Catalysis2.2 Aminocatalysis3 Intermolecular Acyl Transfer with Acyclic Substrates4 Medium-Sized-Ring Formation with Cyclic Substrates5 Conclusion


1998 ◽  
Vol 51 (1) ◽  
pp. 9 ◽  
Author(s):  
Martin G. Banwell ◽  
Brett D. Bissett ◽  
Chinh T. Bui ◽  
Ha T. T. Pham ◽  
Gregory W. Simpson

The oxyanion derived from hydroxyacrylate E-(5) undergoes smooth intramolecular Michael addition to give the trans-2,6-disubstituted tetrahydropyran (7) as the major product of reaction. In contrast, the oxyanion obtained from isomer Z-(5) cyclizes to give the cis-2,6-disubstituted tetrahydropyran (6) as the major product. Such chemistry has been extended to the enantioselective synthesis of (+)-(6) the acquisition of which constitutes a formal total synthesis of acid (+)-(2), a constituent of the glandular secretion from the civet cat (Viverra civetta). Reductive amination of keto acrylate (12) affords an intermediate amine which cyclizes, in situ, to give the cis-2,6-disubstituted piperidine (26). Analogous treatment of compound (13) delivers the isomeric trans-2,6-disubstituted piperidine (27) as the exclusive product of reaction. Transition state structures have been proposed to account for the diastereoselectivities observed in all of the cyclization reactions.


Author(s):  
Douglass F. Taber

Vlada B. Urlacher of the Heinrich-Heine University Düsseldorf showed (Chem. Commun. 2014, 50, 4089) that the P450 monooxygenase CYP154A8 from Nocardia farcinica could monohydroxylate n-octane 1 to 2 with high regioselectivity and ee. Fener Chen of Fudan University used (J. Org. Chem. 2014, 79, 2723) an organocatalyst to open the prochiral anhydride 3 to the monoester 4. Amir H. Hoveyda of Boston College added (Angew. Chem. Int. Ed. 2014, 53, 3387) (pinacolato)borane to the enone 5 to give 6, that was readily oxidized to the tertiary alcohol. Matthias Breuning of the University of Bayreuth designed (Chem. Commun. 2014, 50, 6623) a Cu catalyst for the enantioselective Henry addition of nitromethane to the aldehyde 7 to give 8. Benjamin List of the Max-Planck-Institute für Kohlenforschung optimized (Synlett 2014, 25, 932) the proline-catalyzed formation of the aldol prod­uct 10 from the aldehyde 9. Christian Wolf of Georgetown University devised (Chem. Commun. 2014, 50, 3151) the alkyne 12, that could be added to the aldehyde 11 to give 13 in high ee. Keiji Maruoka of Kyoto University developed (Org. Lett. 2014, 16, 1530) practical conditions for the organocatalyzed addition of an aldehyde 14 to an in situ- generated nitroso urethane, leading, after reduction, to the alcohol 15. Satoko Kezuka of Tokai University added (Tetrahedron Lett. 2014, 55, 2818) the benzyloxyamine 17 to the nitro alkene 16 to give the coupled product 18 in high ee. Xiaohua Liu and Xiaoming Feng of Sichuan University developed (Angew. Chem. Int. Ed. 2014, 53, 1636) a Pd catalyst for the preparation of 20 by the enantioselective amination of the diazo ester 19. Shou-Fei Zhu and Qi-Lin Zhou of Nankai University described (Angew. Chem. Int. Ed. 2014, 53, 2978) related work, not illustrated, on the enantioselective aryloxylation of an α-diazo ester. Alan Armstrong of Imperial College London, taking advantage (J. Org. Chem. 2014, 79, 3895) of the ready availability of enantiomerically secondary selenides such as 21, showed that it could be combined with 22 to give the α-chiral amine 23.


2020 ◽  
Vol 56 (3) ◽  
pp. 439-442 ◽  
Author(s):  
Yong You ◽  
Ting-Ting Li ◽  
Shu-Pei Yuan ◽  
Ke-Xin Xie ◽  
Zhen-Hua Wang ◽  
...  

An asymmetric [4+2] cycloaddition of 1-((2-aryl)vinyl)naphthalen-2-ols with in situ generated ortho-quinone methides enables the highly enantioselective synthesis of polysubstituted chromanes.


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