Organocatalytic enantio- and diastereoselective synthesis of highly substituted δ-lactones via a Michael-cyclization cascade

Agrawal, Santosh; Molleti, Nagaraju; Singh, Vinod K.

doi:10.1039/c5cc02776d

Cited by 19 publications

(5 citation statements)

References 47 publications

(1 reference statement)

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“…It was envisioned that we could use milder conditions and assemble a library of carbamoyl-substituted pyrazoles using a cascade reaction. Such acyl pyrazoles are somewhat scarce in the literature, but have shown to be both bioactive compounds, 20 for example in the core of the agrochemical Dimetilan, and useful building blocks 21 ( Scheme 5 ). The conditions and scope of this cascade reaction are presented in Table 7 .…”

Section: Resultsmentioning

confidence: 99%

Cascade reactions of nitrogen-substituted isocyanates: a new tool in heterocyclic chemistry

et al. 2016

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Section: Resultsmentioning

confidence: 99%

Cascade reactions of nitrogen-substituted isocyanates: a new tool in heterocyclic chemistry

et al. 2016

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“…In 2015, Santosh Agrawal and co‐workers [76] demonstrated an organocatalyzed Michael‐ cyclization cascade approach for the synthesis of highly substituted δ‐lactones. Michael addition of pyrazoleamide 178 to 179 afforded δ‐lactones 180 in decent yields (up to 90 %) with exceptional stereoselectivities (up to >20 : 1 dr, 97 % ee).…”

Section: Organocatalytic Enantioselective Michael Addition Reactionsmentioning

confidence: 99%

Enantioselective Organocatalytic Michael Addition Reactions Catalyzed by Proline/Prolinol/Supported Proline based Organocatalysts: An Overview

Pasuparthy

Maiti

2022

ChemistrySelect

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Ever since the discovery of enantioselective organocatalytic Michael addition reactions, it has emerged as a significant path for synthesizing a variety of stereochemical products under mild conditions, also a prominent C−X (X=C, O, N, S) bond formation reaction in organic chemistry. Over time, substantial progress has been accomplished in diversity‐ and target‐ oriented asymmetric Michael addition reactions. This review provides a brief overview of the results, scope, and limitations of several influential strategies involving enantio‐selective Michael addition reactions promoted by mono‐functional proline/prolinol/supported‐proline‐based chiral organocatalysts. Furthermore, we also sincerely believe that the various synthetic strategies documented in this review will pave a pathway to improve the status of Michael addition reactions for synthesizing various drug molecules involving complex intermediates.

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“…In 2015, the Singh group reported an interesting route to functionalised δ‐lactones which consists of a diastereo‐ and enantioselective Michael/cyclisation cascade process, starting from pyrazoleamides as donor [26] . The reaction involved the Michael addition of pyrazoleamides to aryl substituted α,β‐unsaturated aldehydes, followed by hydrolysis/cyclisation step to afford highly substituted δ‐lactones (Scheme 12).…”

Section: Pyrazoleamides As Nucleophiles In Organocatalysismentioning

confidence: 99%

Pyrazoleamides in Catalytic Asymmetric Reactions: Recent Advances

et al. 2021

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Pyrazoleamides are a class of compounds which have received significant attention in the last years in asymmetric catalysis as more reactive and practical surrogates of esters or amides. These readily available reagents have served in a variety of diastereo-and enantioselective metal-and organocatalytic transformations, spanning from simple carbon-carbon or carbon-heteroatom bond formation to cascade and rearrangement reactions, to produce valuable classes of heterocyclic compounds. More recently, pyrazoleamides have proved to be pertinent reagents in asymmetric catalysis merged with photoredox catalysis, and in more challenging stereoselective bond-forming reactions, occurring directly from a visible-light activated substrate/catalyst complex without any charge separation. Both strategies enable new activation concepts useful for the production of difficult-to-access intermediates and pharmaceuticals. In this review, an overview of the progress achieved in asymmetric catalytic reactions of pyrazoleamides from 2015 up to middle 2020, is illustrated. Rearrangements of α-Diazo Pyrazoleamides 7. Combined Metal-and Organocatalysis 8. Pyrazoleamides in Visible-Light-Activated Photochemical Reactions 8.1. Merging Visible Light Photoredox Activation with Asymmetric Catalysis 8.2. Stereocontrolled Direct Photoreactions from Electronically Excited State 8.3. Merging HAT Photocatalysis with Chiral Lewis Acid Catalysis 9.

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Organocatalytic enantio- and diastereoselective synthesis of highly substituted δ-lactones via a Michael-cyclization cascade

Cited by 19 publications

References 47 publications

Cascade reactions of nitrogen-substituted isocyanates: a new tool in heterocyclic chemistry

Cascade reactions of nitrogen-substituted isocyanates: a new tool in heterocyclic chemistry

Enantioselective Organocatalytic Michael Addition Reactions Catalyzed by Proline/Prolinol/Supported Proline based Organocatalysts: An Overview

Pyrazoleamides in Catalytic Asymmetric Reactions: Recent Advances

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