Organocatalytic Asymmetric Aza‐Michael Additions

Enders, Dieter; Wang, Chuan; Liebich, Jens X.

doi:10.1002/chem.200902236

Cited by 452 publications

(148 citation statements)

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“…This method has attracted much attention due to its mildness and operation simplicity. [31] The spatial orientation of the four macrocycle substituents about the plane of calixarene makes the 1,3-alternate conformation interesting for the synthesis of receptors for dicarboxylic and hydroxycarboxylic acids. Also in the 1,3-alternate conformation, allosteric effect can be realized.…”

Section: Synthesis Of Thiacalix[4]arenesmentioning

confidence: 99%

“…[32] To introduce secondary and tertiary amino groups into the structure of a compound, the aza-Michael reaction can be used. [31] Previously, the derivatives 1 and 2 of tetrasubstituted at lower rim thiacalix [4]arene in 1,3-alternate conformation containing the phthalimide and primary amino fragments, respectively, were synthesized. [11] The interaction of p-tert-butyl-thiacalix [4]arene 2 with acryloyl chloride in the presence of triethylamine and 4-methoxyhydroquinone as a radical polymerization stabilizer resulted in formation of tetraacrylamide 3 in 1,3-alternate conformation (Scheme 1).…”

Section: Synthesis Of Thiacalix[4]arenesmentioning

confidence: 99%

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Secondary Amine Derivatives of p-tert-Butyl Thiacalix[4]arenes: Synthesis and Molecular Recognition of Phthalic Acid

Nosov¹,

Stoikov²

2014

MHC

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New tetrasubstituted p-tert-butylthiacalix[4]arenes containing 2-, 3-, and 4-picolylamine fragments at the lower rim in 1,3-alternate conformation were synthesized. It was shown that the macrocycles synthesized are able to bind selectively phthalic acid in the series of dicarboxylic (oxalic, malonic, succinic, adipic, glutaric, fumaric, maleic, isophthalic and terephthalic) and hydroxy (glycolic and tartaric) acids.

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Section: Synthesis Of Thiacalix[4]arenesmentioning

confidence: 99%

Section: Synthesis Of Thiacalix[4]arenesmentioning

confidence: 99%

Secondary Amine Derivatives of p-tert-Butyl Thiacalix[4]arenes: Synthesis and Molecular Recognition of Phthalic Acid

Nosov¹,

Stoikov²

2014

MHC

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“…Enantioselective epoxidation of cyclic enones. The asymmetric 1,4-conjugate addition of nitrogen nucleophiles to α,β-unsaturated carbonyl compounds allows the preparation of optically active β-amino carbonyl compounds, the key intermediate in the synthesis of many biologically important compounds [7].…”

Section: Scheme 17mentioning

confidence: 99%

“…Since stereogenic centers can be created in the course of the 1,4-conjugate addition reaction, much effort has been made to develop efficient catalytic stereoselective methods [2][3][4][5][6][7][8][9]. Carbocycles with more than one stereocenter are among the most broadly represented synthons found in natural products and medicinal agents.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Organocatalytic Reactions of α,β-Unsaturated Cyclic Ketones

2011

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Abstract:The 1,4-conjugate addition of nucleophiles to α,β-unsaturated carbonyl compounds represents one fundamental bond-forming reaction in organic synthesis. The development of effective organocatalysts for the enantioselective conjugate addition of malonate, nitroalkane and other carbon and heteroatom nucleophiles to cycloenones constitutes an important research field and has been explored in recent years. At the same time, asymmetric Diels-Alder reactions have been developed and often a mechanism has been demonstrated to be a double addition rather than synchronous. This review aims to cover literature up to the end of 2010, describing all the different organocatalytic asymmetric 1,4-conjugate additions even if they are listed as transfer hydrogenation, cycloadditions or desymmetrization of aromatic compounds.

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“…The catalytic asymmetric aza-Michael addition of α,β-unsaturated carboxylic acid derivatives has been extensively investigated as a powerful protocol for the synthesis of optically active β-amino acids, [1][2][3][4] which are frequently encountered as important structural components in biologically active natural products and pharmaceuticals. 5) However, simple α,β-unsaturated esters and amides have only been used in a limited number of successful studies because of their inherent low reactivity as Michael acceptors.…”

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confidence: 99%

Chiral Integrated Catalysts Composed of Bifunctional Thiourea and Arylboronic Acid: Asymmetric Aza-Michael Addition of α,β-Unsaturated Carboxylic Acids

et al. 2016

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The first intermolecular asymmetric Michael addition of nitrogen-nucleophiles to α,β-unsaturated carboxylic acids was achieved through a new type of arylboronic acid equipped with chiral aminothiourea. The use of BnONH 2 as a nucleophile gives a range of enantioenriched β-(benzyloxy)amino acid derivatives in good yields and with high enantioselectivity (up to 90% yield, 97% enantiomeric excess (ee)). The obtained products are efficiently converted to optically active β-amino acid and 1,2-diamine derivatives.Key words aza-Michael addition; α,β-unsaturated carboxylic acid; integrated catalyst; thiourea; arylboronic acid; O-benzylhydroxylamine Stereoselective functionalization of electron-deficient alkenes continues to play a fundamental role in modern organic synthesis. The catalytic asymmetric aza-Michael addition of α,β-unsaturated carboxylic acid derivatives has been extensively investigated as a powerful protocol for the synthesis of optically active β-amino acids, [1][2][3][4] which are frequently encountered as important structural components in biologically active natural products and pharmaceuticals. 5) However, simple α,β-unsaturated esters and amides have only been used in a limited number of successful studies because of their inherent low reactivity as Michael acceptors.6,7) Instead, a variety of activated ester/amide surrogates possessing greater reactivity and rigidity, which enables them to interact with appropriate catalysts, have been developed for the Michael addition.8) Recently, a range of activated carboxylates-specifically, α,β-unsaturated imides, 9,10) acyl pyrroles, 11) and acyl pyrazoles 12) -have been successfully applied in asymmetric metal-and organocatalyzed Michael additions to furnish the desired products with excellent enantioselectivity (Chart 1). However, this masked ester/amide strategy requires a stoichiometric amount of an activating auxiliary and additional protection and deprotection steps. From the perspective of atom and step economy, achieving a direct Michael reaction of α,β-unsaturated carboxylic acids without the use of any activating templates is highly desirable. Despite strong synthetic utility, the direct Michael addition of α,β-unsaturated carboxylic acids has never been reported, except for an enzyme-catalyzed azaMichael addition 13,14) ; very few strategies have been exploited to catalytically activate the hydroxy group of carboxylic acids via transient covalent bond formation.By contrast, since the discovery by Yamamoto and Ishihara that electron-deficient arylboronic acids are efficient activators of carboxylic acids in direct amidation reactions, [15][16][17][18] 24,25) Hall reported that different types of arylboronic acids could be used for the cycloaddition of α,β-unsaturated carboxylic acids to dienes and 1,3-dipoles. 20,21) Recently, we also revealed that aminoarylboronic acid was the best catalyst for the intramolecular hetero-Michael addition of α,β-unsaturated carboxylic acids bearing sulfonamides or phenols.26) In addition, the asymmetric oxa-Michael ...

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Organocatalytic Asymmetric Aza‐Michael Additions

Cited by 452 publications

References 128 publications

Secondary Amine Derivatives of p-tert-Butyl Thiacalix[4]arenes: Synthesis and Molecular Recognition of Phthalic Acid

Secondary Amine Derivatives of p-tert-Butyl Thiacalix[4]arenes: Synthesis and Molecular Recognition of Phthalic Acid

Asymmetric Organocatalytic Reactions of α,β-Unsaturated Cyclic Ketones

Chiral Integrated Catalysts Composed of Bifunctional Thiourea and Arylboronic Acid: Asymmetric Aza-Michael Addition of α,β-Unsaturated Carboxylic Acids

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