Direct Lewis Acid Catalyzed Conversion of Enantioenriched <i>N</i>-Acyloxazolidinones to Chiral Esters, Amides, and Acids

Stevens, Jason M.; Parra-Rivera, Ana Cristina; Dixon, Darryl D.; Beutner, Gregory L.; DelMonte, Albert J.; Frantz, Doug E.; Janey, Jacob M.; Paulson, James; Talley, Michael R.

doi:10.1021/acs.joc.8b02451

Cited by 29 publications

(19 citation statements)

References 83 publications

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“…Finally, the method published by J. Stevens and D. Frantz led to a break‐through: conversion using Yb(OTf) 3 in MeOH enabled the direct oxazolidinone ‐ methoxide exchange, the silylester 18 a was isolated with 96 % yield maintaining the high optical purity (Scheme 3). [43] …”

Section: Resultsmentioning

confidence: 99%

Synthesis of Enantiopure 6,11‐Methylene Lipoxin B₄ Methyl Ester

Trippe

Nava²,

Frank

et al. 2021

Eur J Org Chem

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The synthesis of Lipoxin B4 analogs (LXB4) to gain access to stabilized inflammation resolving compounds is an actual field of research. Focusing on variation and stabilization of the conjugated E,Z,E,E C6–C13 tetraene moiety of natural LXB4, a methylene bridge introduced between C6 and C11 suppresses any Z/E isomerization of the C8–C9 olefin. Intending to enable prospective structure variations in connection with the C1–C5 and C14–C20 fragments, a convergent total synthesis has been developed. Optically active C1–C12 building blocks were build‐up from cycloheptatriene 1‐carbonester (C6–C11, C21) and glutaryl chloride (C1–C5) using Friedel‐Crafts‐type acylation and chiral HPLC. The C13–C20 segment had been generated via a five‐step sequence starting from heptanoyl chloride. Horner key olefination enabled the assembly of the carbon backbone. A final five‐step sequence including a chelate Cram reduction of the unsaturated ketone moiety afforded the target 6,11‐methylene LXB4 methyl ester.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Enantiopure 6,11‐Methylene Lipoxin B₄ Methyl Ester

Trippe

Nava²,

Frank

et al. 2021

Eur J Org Chem

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“…Stevens et al [74] have utilized HTE to identify Lewis acids for converting N-acyloxazolidinone intermediates to esters and amides containing an α-stereocenter in a single step with high selectivity (Scheme 6b). Screening of 24 different Lewis acids in methanol and ethanol as solvent using two different substrates at 65°C for 24 hours was conducted.…”

Section: Cà O Bond Forming Reactionsmentioning

confidence: 99%

“…Stevens et al [74] . have utilized HTE to identify Lewis acids for converting N‐acyloxazolidinone intermediates to esters and amides containing an α‐stereocenter in a single step with high selectivity (Scheme 6b).…”

Section: C−x Bond Forming Reactionsmentioning

confidence: 99%

Advancement in Organic Synthesis Through High Throughput Experimentation

2021

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and cyanoarenes has also been optimized using an HTE approach. [63] Other Photochemical TransformationsNon-activated alkyl bromides were coupled with Michael acceptors in a photoredox Giese-type reaction. [64] Reaction optimization was performed by studying the effect of photocatalyst, solvent, base, and varying amounts of radical initiator (Me 3 Si) 3 SiH on product and by-product profile. Another study of conjugate addition using photocatalytic methodology was shown for the synthesis of unnatural β-alkyl α-amino acid derivatives via decarboxylative photocatalysis. [65] Photocatalysis was performed with oxime and cyanopyridine precursors (Scheme 4g) to form primary amine products. [66] Four different solvents (acetone, DCE, ACN, DMSO), nine different photocatalysts, and two reductants were used to evaluate 45 unique reactions. DMSO with diisopropylamine and Ir[dF(Me) ppy] 2 dtbbpyPF 6 gave the highest yield by UPLC, although many Scheme 4. Photocatalytic transformations in HTE.

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“…1,3-Oxazolidin-2-ones represent valuable and highly reactive five-membered heterocyclic ring systems in organic chemistry due to their broad recognized versatility as building blocks for many organic transformations [52][53][54][55]. Some of them serve as excellent precursors for various nitrogencontaining heterocyclic compounds of synthetic and biological interest [56][57][58][59][60][61]. However, there are very few reports in the literature for the conversion of oxazolidin-2-ones into oxazol-2-ones [62][63][64][65][66][67][68].…”

Section: Introductionmentioning

confidence: 99%