Synthesis of novel β-amino alcohols and their application in the catalytic asymmetric sulfoxidation of sulfides

Aydin, A. Ebru

doi:10.1016/j.tetasy.2013.03.011

Cited by 17 publications

(5 citation statements)

References 71 publications

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“…Modified Schiff bases were introduced by several research groups as chiral tridendate ligands for vanadium(IV), typically applied as VO(acac) 2 in a two-phase system with hydrogen peroxide as oxidant. − Manganese was used in combination of salen , or another tetradendate, N4 ligand 8 ; the latter, with carboxylic acid 9 as additive and H 2 O 2 as oxidant, allowed highly enantioselective, gram-scale preparation of various sulfoxides also in the flow system (Scheme ). − Chiral salen-type Fe(III) complexes were also used in successful sulfoxidations with peroxides. , Nishiguchi et al applied iron(III) complex with a Schiff base 11 in preparation of proton pump inhibitors and received esomeprazole 2 in 87% yield (12% of sulfone was formed) and >99% ee (Scheme ).…”

Section: Preparation Of Chiral Nonracemic Sulfoxidesmentioning

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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Section: Preparation Of Chiral Nonracemic Sulfoxidesmentioning

confidence: 99%

Modern Stereoselective Synthesis of Chiral Sulfinyl Compounds

2020

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“…Synthesis of chiral diamine 10. According to our previously procedure, 46,47 the formylation of 2-methyl thiophene was performed according to Vismeier Haack method. 5-Methyl thiophene-2-carbaldehyde 8 (5mmol) were dissolved in 10 mL benzene to which was added (1S,2S)-1,2-diphenylethane-1,2-diamine (5 mmol) under nitrogen atmosphere.…”

Section: Synthesis Of Chiral Catalysts 7a-dmentioning

confidence: 99%

Chiral thiourea derivatives as organocatalyts in the enantioselective Morita-Baylis-Hillman reactions

Aydin¹

2020

Arkivoc

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Novel chiral bifunctional thiourea derivatives have been synthesised and successfully applied to the intermolecular Morita-Baylis-Hillman (MBH) reaction of an aromatic aldehyde with methyl vinyl ketone (MVK) and to the intramolecular MBH reaction of ω-formyl-enone. The corresponding products were obtained with high enantioselectivities (up to 98% ee). The thiourea organocatalyst derived from a β-amino alcohol gave high enantioselectivities (92% ee) in the intermolecular MBH reaction, whereas the same chiral ligand afforded the corresponding product in high yield (85%) with moderate enantioselectivity (75% ee) in the intramolecular MBH reaction. The use of a thiophene ring-containing thiourea derivative gave high enantioselectivities in the intermolecular and intramolecular MBH reactions (85% and 95% ee, respectively).

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“…The enantioselective sulfoxidation of prochiral sulfides is one of the most challenging approaches to chiral sulfoxides, and catalyzed processes based on metal complexes [ 3 , 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] and metal-free systems [ 17 ] have been described in the literature. Molybdenum-catalyzed enantioselective sulfoxidations have been investigated [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ] and, in general, the Mo catalysts provided results that are somewhat lower than those of other metals, as for example titanium [ 26 , 27 , 28 , 29 , 30 , 31 , 32 ] or vanadium [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] complexes. However, we have recently demonstrated that the use of the imidazolium-based dicarboxylic compound ( S , S )-1-(1-carboxy-2-methylpropyl)-3-(1-carboxylate-2-methylpropyl)imidazolium (HL iPr in Scheme 1 ), as inductor of chirality, in combination with oxidoperoxidomolybdenum complexes, afforded a system capable to achieve by kinetic resolution a value of 83% ee in the sulfoxidation of alkyl aryl sulfides [ 42 ].…”

Section: Introductionmentioning

confidence: 99%

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands

2018

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Chiral alkyl aryl sulfoxides were obtained by molybdenum-catalyzed oxidation of alkyl aryl sulfides with hydrogen peroxide as oxidant in mild conditions with high yields and moderate enantioselectivities. The asymmetry is generated by the use of imidazolium-based dicarboxylic compounds, HLR. The in-situ-generated catalyst, a mixture of aqueous [Mo(O)(O2)2(H2O)n] with HLR as chirality inductors, in the presence of [PPh4]Br, was identified as the anionic binuclear complex [PPh4]{[Mo(O)(O2)2(H2O)]2(μ-LR)}, according to spectroscopic data and Density Functional Theory (DFT) calculations. A nonclassical hydrogen bond between one C–H bond of the alkyl R group of coordinated (LR)− and one oxygen atom of the peroxido ligand was identified as the interaction responsible for the asymmetry in the process. Additionally, the step that governs the enantioselectivity was theoretically analyzed by locating the transition states of the oxido-transfer to PhMeS of model complexes [Mo(O)(O2)2(H2O)(κ1-O-LR)]− (R = H, iPr). The ∆∆G≠ is ca. 0 kcal∙mol−1 for R = H, racemic sulfoxide, meanwhile for chiral species the ∆∆G≠ of ca. 2 kcal∙mol−1 favors the formation of (R)-sulfoxide.

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Synthesis of novel β-amino alcohols and their application in the catalytic asymmetric sulfoxidation of sulfides

Cited by 17 publications

References 71 publications

Modern Stereoselective Synthesis of Chiral Sulfinyl Compounds

Modern Stereoselective Synthesis of Chiral Sulfinyl Compounds

Chiral thiourea derivatives as organocatalyts in the enantioselective Morita-Baylis-Hillman reactions

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands

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