Acid-catalysed conversion of sulphinamides into sulphinates: a new synthesis of optically active sulphinates

Mikołajczyk, M.; Drabowicz, J.; Bujnicki, Bogdan

doi:10.1039/c39760000568

Cited by 41 publications

(14 citation statements)

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“…It is remarkable that the N -(diphenylmethylene) group was not removed under these reaction conditions but was trapped by the deprotected β-amino group, as the deprotection of analogous anti -substrates under the same reaction conditions led to unprotected anti -α,β-diaminocarboxyl esters [18]. This is possibly due to the fact that solvolysis of the imine functionality with ethanol is not favorable and an acid-catalyzed deprotection of the sulfinyl moiety will occur first [41–42]. The resulting β-amino deprotected syn -γ-chloro-α,β-diaminocarboxylamide could subsequently ring close further to trans -imidazolidine 12b , which will be less sterically congested than an analogous cis -imidazolidine.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric synthesis of γ-chloro-α,β-diamino- and β,γ-aziridino-α-aminoacylpyrrolidines and -piperidines via stereoselective Mannich-type additions of N-(diphenylmethylene)glycinamides across α-chloro-N-sulfinylimines

Callebaut

Mangelinckx²,

Veken³

et al. 2012

Beilstein J. Org. Chem.

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SummaryThe asymmetric synthesis of new chiral γ-chloro-α,β-diaminocarboxylamide derivatives by highly diastereoselective Mannich-type reactions of N-(diphenylmethylene)glycinamides across chiral α-chloro-N-p-toluenesulfinylaldimines was developed. The resulting (S S,2S,3S)-γ-chloro-α,β-diaminocarboxylamides were formed with the opposite enantiotopic face selectivity as compared to the (S S,2R,3R)-γ-chloro-α,β-diaminocarboxyl esters obtained via Mannich-type addition of analogous N-(diphenylmethylene)glycine esters across a chiral α-chloro-N-p-toluenesulfinylaldimine. Selective deprotection under different acidic reaction conditions and ring closure of the γ-chloro-α,β-diaminocarboxylamides was optimized, which resulted in Nα-deprotected syn-γ-chloro-α,β-diaminocarboxylamides, N-sulfinyl-β,γ-aziridino-α-aminocarboxylamide derivatives, a trans-imidazolidine, and an Nα,Nβ-deprotected syn-γ-chloro-α,β-diaminocarboxylamide.

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Section: Resultsmentioning

confidence: 99%

Asymmetric synthesis of γ-chloro-α,β-diamino- and β,γ-aziridino-α-aminoacylpyrrolidines and -piperidines via stereoselective Mannich-type additions of N-(diphenylmethylene)glycinamides across α-chloro-N-sulfinylimines

Callebaut

Mangelinckx²,

Veken³

et al. 2012

Beilstein J. Org. Chem.

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“…Conversion of enantiomerically enriched sulfinamides to sulfinates in the presence of strong acids was shown to proceed with a predominant inversion of configuration. 165 ( S )- N , N -Diethyl p -toluene sulfinamide was first prepared from the corresponding menthyl sulfinate and Et 2 NMgBr. Its reactions with alcohols were found to proceed with medium to excellent stereospecifity, dependent mainly on the structure of alcohols; a complete inversion was observed for primary ones, and the steric hindrance exerted by secondary and tertiary alcohols resulted in partial racemization.…”

Section: Stereoselective Synthesis Of Sulfinatesmentioning

confidence: 99%

Modern Stereoselective Synthesis of Chiral Sulfinyl Compounds

2020

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Chiral sulfinyl compounds, sulfoxides, sulfoximines, sulfinamides, and other derivatives, play an important role in asymmetric synthesis as versatile auxiliaries, ligands, and catalysts. They are also recognized as pharmacophores found in already marketed and well-sold drugs (e.g., esomeprazole) and used in drug design. This review is devoted to the modern methods of preparation of sulfinyl derivatives in enantiopure or enantiomerically enriched form. Selected new approaches leading to racemic products for which the asymmetric variant can be developed in the future are mentioned as well.

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“…The aminophosphonate (þ)-15a isolated in this way was subsequently converted to b-aminophosphonate (À)-16a by trifluoroacetic acid-catalyzed methanolysis, 8 resulting in a selective deprotection of the amino group and to (þ)-b-aminob-phenylethanephosphonic acid (þ)-17 by heating under reflux for 7 h in a mixture of glacial acetic acid and hydrochloric acid. 9 The chirality at the b-carbon atom in (þ)-17 was established as (R) by a single-crystal X-ray analysis.…”

Section: Enantioselective C-c Bond-forming Reactionsmentioning

confidence: 99%