α-Pinene-type chiral Schiff bases as tridentate ligands in asymmetric addition reactions

Jaworska, M.; Błocka, Ewelina; Kozakiewicz, Anna; Wełniak, Mirosław

doi:10.1016/j.tetasy.2011.03.013

Cited by 17 publications

(8 citation statements)

References 28 publications

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“…In this context, Jaworska et al. have reported the synthesis of chiral Schiff bases derived from α‐pinene and their application as tridentate ligands for the silylcyanation reaction of aldehydes 18. Among several ligands bearing various substituents on the phenolic ring, ligand 2 was selected to be the most efficient, providing at 20 mol% of catalyst loading, cyanohydrins of aliphatic and aromatic aldehydes in moderate enantioselectivities of up to 62% ee (Scheme ).…”

Section: Titanium‐catalyzed Cyanations Of Aldehydesmentioning

confidence: 99%

Kongresse – Symposien – Seminare – Messen

2014

Beton und Stahlbetonbau

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This review surveys the recent developments in enantioselective titanium‐catalyzed cyanation reactions of carbonyl compounds, covering the literature since the beginning of 2008. It well demonstrates that this reaction constitutes an important tool in organic synthesis, still attracting a considerable interest due to the potential use of enantiopure cyanohydrins as natural products and useful synthetic intermediates in the synthesis of biologically active molecules. Abbreviations: Ac: acetyl; Ar: aryl; BINOL: 1,1′‐bi‐2‐naphthol; BINOLAM: bis(diethylaminomethyl)‐1,1‘‐binaphthol; Bn: benzyl; Cy: cyclohexyl; DFT: density functional theory; DMAP: 4‐(dimethylamino)pyridine; ee: enantiomeric excess; Naph: naphthyl; r.t.: room temperature; salen: 1,2‐bis(salicylidenamino)ethane; TADDOL: α,α,α′,α′‐tetraphenyl‐2,2‐dimethyl‐1,3‐dioxolane‐4,5‐dimethanol; TEA: trimethylamine; THF: tetrahydrofuran; TMS: trimethylsilyl; Tol: tolyl.

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Section: Titanium‐catalyzed Cyanations Of Aldehydesmentioning

confidence: 99%

Kongresse – Symposien – Seminare – Messen

2014

Beton und Stahlbetonbau

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“…Several natural, chiral terpenes, including (+)-pulegone [5][6][7], -and -pinene [8][9][10][11] and fenchone-camphor [12][13][14], have been found to be excellent sources for the production of various amino alcohols, which have been successfully applied in enantioselective syntheses [1,4]. The transformation of enantiomerically purepinene to -amino acid derivatives such as 1,3-aminoalcohols was recently reported [3,10,15,16], and these synthons have proved to be useful chiral auxiliaries in the enantioselective synthesis of secondary alcohols or pharmacons, e.g.…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis and Antiproliferative Activity of Monoterpene-Fused 2- Imino-1,3-oxazines

Szakonyi

Zupkó

Fueloep

2017

COS

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Background: In the recent years the 2-imino-1,3-thiazine and 2-iminothiazolidine ring systems can be found as moieties in biologically relevant compounds, including BACE1 inhibitors, or cannabinoid receptor agonists, while monoterpene-based 2-imino-1,3-thiazines, prepared from chiral 1,3-amino alcohols exhibiting pronounced antiproliferative activity. Methods:The antiproliferative activities of the prepared compounds were determined in vitro against a panel of human adherent cancer cell lines including HeLa, MCF7 and A431 by MTT assay. Results:Starting from pinane-, apopinane-and carane-based -amino acid derivatives, 1,3-amino alcohols were prepared via two-step syntheses. The reactions of the product 1,3-amino alcohols and aryl isothiocyanates yielded -hydroxythioureas, which were transformed to monoterpene-fused 2-imino-1,3-oxazines via base-catalysed ring closure. The antiproliferative activities of these 2-imino-1,3-oxazines were examined and the structure-activity relationships were studied from the aspects of the type and stereochemistry of the monoterpene ring and the substituent effects on the 1,3-oxazine ring system. The N-unsubstituted monoterpene-based derivatives exhibited considerable antiproliferative activity against a panel of human adherent cancer cell lines (HeLa, MCF7 and A431). Conclusions:A mild and efficient method has been developed for the synthesis of 2-imino-1,3-oxazines by the ring closure of thiourea adducts of 1,3-amino alcohols. The resulting 1,3-oxazines exert marked antiproliferative action on a panel of human cancer cell lines.

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“…Several natural chiral terpenes, including (+)-pulegone [4,5,6] α- and β-pinene [7,8,9] and fenchone-camphor [10,11,12], have proved to be excellent sources for the production of various amino alcohols, which have been successfully applied in enantioselective syntheses. The transformation of enantiomerically pure α-pinene to β-amino acid derivatives such as 1,3-amino alcohols was recently reported [9,13].…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines

et al. 2014

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Abstract:Starting from pinane-, apopinane-and carane-based 1,3-amino alcohols obtained from monoterpene-based β-amino acids, a library of monoterpene-fused 2-imino-1,3-thiazines as main products and 2-thioxo-1,3-oxazines as side-products were prepared via two-or three-step syntheses. When thiourea adducts prepared from 1,3-amino alcohols and aryl isothiocyanates were reacted with CDI under mild conditions, O-imidazolylcarbonyl intermediates were isolated which could be transformed to the desired 1,3-thiazines under microwave conditions. 1,3-Thiazines and 2-thioxo-1,3-oxazine side-products could also be prepared in one-step reactions through the application of CDI and microwave irradiation. The ring-closure process was extended to cycloalkane-based γ-hydroxythioureas. The carane-and apopinane-based derivatives exhibited marked antiproliferative activity against a panel of human adherent cancer cell lines (HeLa, A2780, MCF7 and A431).

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α-Pinene-type chiral Schiff bases as tridentate ligands in asymmetric addition reactions

Cited by 17 publications

References 28 publications

Kongresse – Symposien – Seminare – Messen

Kongresse – Symposien – Seminare – Messen

Stereoselective Synthesis and Antiproliferative Activity of Monoterpene-Fused 2- Imino-1,3-oxazines

Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines

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