Assessing the scope of the tandem Michael/intramolecular aldol reaction mediated by secondary amines, thiols and phosphines

Richards, Elinor; Murphy, P. J.; Dinon, Francesca; Fratucello, Silvia; Brown, Paul M.; Gelbrich, Thomas; Hursthouse, Michael B.

doi:10.1016/s0040-4020(01)00744-x

Cited by 64 publications

(39 citation statements)

References 22 publications

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“…General Procedure for the Preparation of 2: A solution of catalyst II (41 mg, 0.13 mmol) and acetic acid (8 mg, 0.13 mmol) in CH 2 Cl 2 (1 mL) was added dropwise to a solution of ( E )‐ 1 (102 mg, 0.6 mmol)25 and trans ‐nitrostyrene (75 mg, 0.5 mmol) in CH 2 Cl 2 (2 mL). The solution was stirred for 1 h, diluted with EtOAc (10 mL), washed with brine (2 mL), dried with Na 2 SO 4 , and concentrated in vacuo to give the crude product.…”

Section: Methodsmentioning

confidence: 99%

Organocatalytic Double Michael Reaction of 7‐Oxohept‐2‐enoates and Nitrostyrene – Formal Synthesis of (–)‐α‐ and (–)‐β‐Lycorane

Hong

Nimje

et al. 2008

Eur J Org Chem

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Keywords: Asymmetric synthesis / Organocatalysis / Michael additions / Domino reactions / Tandem reactionsOrganocatalytic conjugate addition of 7-oxohept-2-enoate to nitrostyrene provided an ω-nitro-α,β-unsaturated ester. Subsequent intramolecular cyclization afforded the highly functionalized cyclohexane carboester with four stereogenic centers with high diastereoselectivity and high enantioselectivity (Ͼ99 % ee). Some adducts were transformed into

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Section: Methodsmentioning

confidence: 99%

Organocatalytic Double Michael Reaction of 7‐Oxohept‐2‐enoates and Nitrostyrene – Formal Synthesis of (–)‐α‐ and (–)‐β‐Lycorane

Hong

Nimje

et al. 2008

Eur J Org Chem

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“…The absolute configuration of the intermolecular MBH products, R, was assigned by comparing the retention time (chiral HPLC) with its literature values. 23,30,31,33,48 Because 7a gave the highest enantioselectivity in the MBH reaction of p-nitrobenzaldehyde with MVK, it was identified as most effective among the chiral ligand series (Table 1, entry 10) and was selected for optimising further the reaction conditions.…”

Section: © Author(s)mentioning

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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“…Secondary amines were recognized to promote intramolecular cyclizations of enonealdehydes thereby yielding MBH products. The reaction was interpreted, however, as involving a tandem Michael/aldol condensation [ 132 , 133 , 134 ]. To the best of our knowledge the first reported attempt at employing a secondary amine such as ( S )-proline as enantioselective catalyst for MBH reactions is due to Shi and coworkers [ 135 ].…”

Section: The α-Aminoacid Catalyzed and α-Aminoacid-amine Cocatalyzmentioning

confidence: 99%

Enantioselective, Organocatalytic Morita-Baylis-Hillman and Aza-Morita-Baylis-Hillman Reactions: Stereochemical Issues

Mansilla

Saá

2010

Molecules

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Conscious of the importance that stereochemical issues may have on the design of efficient organocatalyts for both Morita-Baylis-Hillman and aza-Morita-Baylis-Hillman reaction we have analyzed them in this minireview. The so-called standard reactions involve “naked” enolates which therefore should lead to the syn adducts as the major products, irrespective of the E, Z stereochemistry of the enolate. Accordingly, provided the second step is rate determining step, the design of successful bifunctional or polyfunctional catalysts has to consider the geometrical requirements imposed by the transition structures of the second step of these reactions. On the other hand, MBH and aza-MBH reactions co-catalyzed by (S)-proline and a secondary or tertiary amine (co-catalyst) involve the aldol-type condensation of either a 3-amino-substituted enamine, dienamine, or both, depending on the cases. A Zimmerman-Traxler mechanism defines the stereochemical issues regarding these co-catalyzed condensations which parallel those of the well established (S)-proline catalyzed aldol-like reactions.

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Assessing the scope of the tandem Michael/intramolecular aldol reaction mediated by secondary amines, thiols and phosphines

Cited by 64 publications

References 22 publications

Organocatalytic Double Michael Reaction of 7‐Oxohept‐2‐enoates and Nitrostyrene – Formal Synthesis of (–)‐α‐ and (–)‐β‐Lycorane

Organocatalytic Double Michael Reaction of 7‐Oxohept‐2‐enoates and Nitrostyrene – Formal Synthesis of (–)‐α‐ and (–)‐β‐Lycorane

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

Enantioselective, Organocatalytic Morita-Baylis-Hillman and Aza-Morita-Baylis-Hillman Reactions: Stereochemical Issues

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