Regio- and diastereoselective construction of a new set of functionalized pyrrolidine, spiropyrrolidine and spiropyrrolizidine scaffolds appended with aryl- and heteroaryl moieties via the azomethine ylide cycloadditions
“…Absorbance was recorded at 405/750 nm which corresponds to the free monomeric heme. The persistence of malaria parasites is dependent on hemozoin crystallization, which has sparked interest in the development of novel antimalarial drugs [ [31] , [32] , [33] , [34] ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…The reaction mixture was then allowed to reflux for 24 h. A yellow precipitate formed during the course of the reaction was filtered and washed with chilled ethanol, dried, and recrystallized from ethanol to afford pure product [ 32 ]. All the chalcones were reported earlier [ [33] , [34] , [35] ].…”
“…Absorbance was recorded at 405/750 nm which corresponds to the free monomeric heme. The persistence of malaria parasites is dependent on hemozoin crystallization, which has sparked interest in the development of novel antimalarial drugs [ [31] , [32] , [33] , [34] ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…The reaction mixture was then allowed to reflux for 24 h. A yellow precipitate formed during the course of the reaction was filtered and washed with chilled ethanol, dried, and recrystallized from ethanol to afford pure product [ 32 ]. All the chalcones were reported earlier [ [33] , [34] , [35] ].…”
“…In general, the chemical yields and the diastereoselection were very high (Scheme 14). 32 Spirooxindole-fused cycloadducts 60 and 61 were reported by Perumal et al from thiazolidine-4-carboxylic acid (18, X = S) or sarcosine (13) and substituted isatins 2 as source of azomethine ylide intermediates. The 1,3-DC with benzimidazolylphenylacrylonitrile 59 as dipolarophile occurred, in refluxing methanol, in very high yields and excellent diastereoselection (Scheme 15).…”
Section: Short Review Syn Thesismentioning
confidence: 97%
“…A study of the biological properties of these compounds is in progress. 32 The 1,3-DC has been considered the key step in a new approach to the synthesis of fused benzodiazepines 182. Firstly, the thermal multicomponent 1,3-DC took place in the presence of alanine derivative 180, 2-azidobenzaldehyde (66), and maleimides 94 in short reaction times (Scheme 53).…”
In this revision a summary of the trends of the formation of complex or not so complex heterocyclic structures through 1,3-DC of azomethine ylides is described. Diastereo-and enantioselective processes as well as nonasymmetric cycloadditions constitute very important synthetic tools for achieving all these series of compounds. The contents are classified as follows: 1. Introduction 2. Synthesis of spiroxindoles 3. Synthesis of spiropyrrolidines 4. Synthesis of spiropiperidines and piperidines 5. Synthesis of pyrrolidines and fused pyrrolidines 6. Synthesis of pyrrolizidines and indolizidines 7. Synthesis of quinolone and isoquinolines 8. Conclusions
“…[3][4][5][6][7][8][9][10][11][12] More interesting is the asymmetric version of this reaction, which allows to obtain up to 4 stereogenic centers in one reaction step in a selective manner, classically achieved by the use of metal-or organocatalysis. [13][14][15][16][17][18][19][20][21] The origin of the exo/endo selectivity in the catalytic asymmetric synthesis of pyrrolidines by 1,3-dipolar cycloaddition of azomethine ylides has been brilliantly rationalized and reported recently. [22] The reaction between azomethine ylides and sulfinyl or sulfonyl groups has been reported in the past, with diverse results.…”
The novel enantiopure synthesis of protected proline-cysteine analogs by means of 1,3-dipolar cycloaddition of homochiral thiazolines and azomethine ylides is described. The important role of the oxidation state of the sulfur atom of the dipolarophile in such reaction is demonstrated affecting strongly the regioselectivity and reactivity of the 1,3-dipolar cycloaddition. Mono-oxidized sulfur atom (sulfoxide group) and di-oxidized (sulfone group) led to 2,3 regio-addition whereas reactions starting from non-oxidized sulfur atom resulted in the 2,4 addition. Besides, sulfur oxidized thiazolines reacted smoothly upon heating in an organic solvent media but the non-oxidized sulfur thiazoline required metal catalysis. Diastereofacial selectivity was observed to be independent of the oxidation state of the sulfur atom but controlled by the bulky tert-butyl group at the thiazoline ring. The highly substituted and functionalized enantiopure pyrrolidine-thiazolidine bicyclic compounds are considered as novel (homo)cysteine-proline analogs with important properties to discover.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
