Synthesis and Investigation of Pinane-Based Chiral Tridentate Ligands in the Asymmetric Addition of Diethylzinc to Aldehydes

Raji, Mounir; Lê, Thạch Ngọc; Fülöp, Ferenc; Szakonyi, Zsolt

doi:10.3390/catal10050474

Cited by 6 publications

(6 citation statements)

References 69 publications

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“…It is probably due to the steric hindrance from the two methyl groups on the pinane system that the hydride could only approach the carbonyl carbon from the Si side. 24 When ring opening of epoxide 5 was attempted with different reductants, such as L-Selectride and LiAlH 4 or by applying epoxide hydrolysis under acidic or alkaline conditions, the opening process failed.…”

Section: Scheme 2 Hydrogenation Of 23-unsaturated Amino Alcoholmentioning

confidence: 99%

Stereoselective Synthesis and Applications of Pinane-Based Chiral 1,4-Amino Alcohol Derivatives

et al. 2022

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A new library of pinane-based 1,4-amino alcohols was synthesised and utilised as chiral ligands in enantioselective diethylzinc addition to benzaldehyde. Aldol condensation of (+)-nopinone, derived from (–)-β-pinene, with 2-pyridinecarboxaldehyde gave the key intermediate α,β-unsaturated ketone, which was transformed in diastereoselective reduction, followed by hydrogenation, resulting in 1,4-amino alcohols. On the other hand, epoxidation of the α,β-unsaturated ketone, followed by reduction and then hydrogenation of the pyridine ring, afforded a mixture of 4-amino-2,3-epoxy-1-ols. Stereoselective hydride reduction of the epoxy ketone and subsequent condensation of the resulting products with substituted benzyl bromides provided quaternary ammonium salts, which were subjected to hydride reduction and then hydrogenation, affording 4-amino-2,3-epoxy-1-ol derivatives containing an N-benzylpiperidine moiety. The inhibition of nucleophile-initiated opening of the oxirane ring was interpreted by a systematic series of comparative Hartree–Fock modelling study using the 6-31+G(d,p) basis set. The antiproliferative activities of 4-amino-2,3-epoxy-1-ol derivatives were examined, and structure–activity relationships were studied from the aspects of the stereochemistry of the oxirane ring, saturation, and substituent effects on the piperidine ring system.

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Section: Scheme 2 Hydrogenation Of 23-unsaturated Amino Alcoholmentioning

confidence: 99%

Stereoselective Synthesis and Applications of Pinane-Based Chiral 1,4-Amino Alcohol Derivatives

et al. 2022

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“…The aforementioned reactions performed in the presence of atropisomeric 1-phenylpyrroles 93 and 94 led to the opposite enantiomers of desired alcohol with high enantioselectivity (Scheme 34) [85]. Recent developments towards efficient, highly enantioselective addition of diethylzinc to aldehydes include the use of chiral derivatives such as (Figure 2): 5-cis-substituted proline derivatives (prolinols 95 and prolinamines 96) [86], proline-based N,N-dioxides 97 [87], pinane-based tridentate ligands 98 [88], axially chiral tridentate isoquinolinederived ligands 99 [89], chiral oxazoline-based systems 100 [90], thiophene-derived amino alcohols 101 [91], amino alcohols 102 [92], noscapine-derived β-amino alcohols 103 [93,94], chiral ferrocene and ruthenocene substituted aminomethylnaphthols 104 [95], and chiral P,N-ligands 105 [96]. Enantioselective aldol-type reaction of trifluorodiazomethane 109 with various aldehydes was efficiently catalyzed by quinine in the presence of diethylzinc in THF (Scheme 36) [98].…”

Section: Asymmetric Reactions In the Presence Of Zinc Ionsmentioning

confidence: 99%

Recent Advances in Selected Asymmetric Reactions Promoted by Chiral Catalysts: Cyclopropanations, Friedel–Crafts, Mannich, Michael and Other Zinc-Mediated Processes—An Update

2021

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The main purpose of this review article is to present selected asymmetric synthesis reactions in which chemical and stereochemical outcomes are dependent on the use of an appropriate chiral catalyst. Optically pure or enantiomerically enriched products of such transformations may find further applications in various fields. Among an extremely wide variety of asymmetric reactions catalyzed by chiral systems, we are interested in: asymmetric cyclopropanation, Friedel–Crafts reaction, Mannich and Michael reaction, and other stereoselective processes conducted in the presence of zinc ions. This paper describes the achievements of the above-mentioned asymmetric transformations in the last three years. The choice of reactions is related to the research that has been carried out in our laboratory for many years.

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“…Besides their biological interest, aminodiols have also been applied as starting materials in asymmetric syntheses or as chiral auxiliaries and ligands in enantioselective transformations [1,[16][17][18]. To develop new, efficient, and commercially available chiral catalysts, chiral natural products including (+)-and (−)-α-pinene [19,20], (−)-nopinone [21], (+)-carene [22,23], (+)-sabinol [24], (−)-pulegone [25], or camphore and fenchon [26] can serve as important starting materials for the synthesis of aminodiols. Monoterpene-based aminodiols have been demonstrated to be excellent chiral auxiliaries in a wide range of stereoselective transformations, including Grignard addition [27,28] and intramolecular radical cyclisation [29].…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis and Catalytical Application of Perillaldehyde-Based 3-Amino-1,2-diol Regioisomers

Háznagy,

Csámpai,

Ugrai

et al. 2024

IJMS

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A library of regioisomeric monoterpene-based aminodiols was synthesised and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The synthesis of the first type of aminodiols was achieved starting from (−)-8,9-dihydroperillaldehyde via reductive amination, followed by Boc protection and dihydroxylation with the OsO4/NMO system. Separation of formed stereoisomers resulted in a library of aminodiol diastereoisomers. The library of regioisomeric analogues was obtained starting from (−)-8,9-dihydroperillic alcohol, which was transformed into a mixture of allylic trichloroacetamides via Overman rearrangement. Changing the protecting group to a Boc function, the protected enamines were subjected to dihydroxylation with the OsO4/NMO system, leading to a 71:16:13 mixture of diastereoisomers, which were separated, affording the three isomers in isolated form. The obtained primary aminodiols were transformed into secondary derivatives. The regioselectivity of the ring closure of the N-benzyl-substituted aminodiols with formaldehyde was also investigated, resulting in 1,3-oxazines in an exclusive manner. To explain the stability difference between diastereoisomeric 1,3-oxazines, a series of comparative theoretical modelling studies was carried out. The obtained potential catalysts were applied in the reaction of aromatic aldehydes and diethylzinc with moderate to good enantioselectivities (up to 94% ee), whereas the opposite chiral selectivity was observed between secondary aminodiols and their ring-closed 1,3-oxazine analogues.

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Synthesis and Investigation of Pinane-Based Chiral Tridentate Ligands in the Asymmetric Addition of Diethylzinc to Aldehydes

Cited by 6 publications

References 69 publications

Stereoselective Synthesis and Applications of Pinane-Based Chiral 1,4-Amino Alcohol Derivatives

Stereoselective Synthesis and Applications of Pinane-Based Chiral 1,4-Amino Alcohol Derivatives

Recent Advances in Selected Asymmetric Reactions Promoted by Chiral Catalysts: Cyclopropanations, Friedel–Crafts, Mannich, Michael and Other Zinc-Mediated Processes—An Update

Stereoselective Synthesis and Catalytical Application of Perillaldehyde-Based 3-Amino-1,2-diol Regioisomers

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