Highly efficient construction of chiral dispirocyclic oxindole/thiobutyrolactam/chromanone complexes through Michael/cyclization cascade reactions with a rosin-based squaramide catalyst

Lin, Ning; Long, Xian-wen; Qing, Chen; Zhu, Weiwei; Wang, Bi-Chuan; Chen, Kai-Bin; Jiang, Cai-Wu; Weng, Jiang; Lu, Gui

doi:10.1016/j.tet.2018.05.052

Cited by 28 publications

(14 citation statements)

References 57 publications

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“…Moreover, the reaction was attempted with cyclic chalcones which afforded bispirocyclic molecules (Scheme 57). Along this line, the same protocol has been applied with unsaturated chromanones as the Michael acceptor partner in presence of rosin based squaramide catalyst to prepare same type of bispirocyclic motifs (not shown in the scheme [95] ).…”

Section: Synthesis Of Five‐ Membered Ringsmentioning

confidence: 99%

Squaramide Catalyzed Asymmetric Synthesis of Five‐ and Six‐Membered Rings

Biswas¹,

Ghosh

Shankhdhar

et al. 2021

Asian J Org Chem

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Chiral analogues of squaramides have been fruitful in organocatalyzed asymmetric reactions over last decade. Alongside other H-bonding catalysts like ureas, thioureas: squaramides have been proved to be efficient asymmetric catalysts for the formation of acyclic and cyclic chiral molecules. A wide range of cyclic molecules bearing multiple functionalities and stereocenters have been synthesized by using several bifunctional squaramides as catalysts. These catalysts perform as base utilizing basic N atom in their chiral extension and help in stereoinduction by forming H-bonds with suitable H-bond acceptors. The present review focuses on assembling recent progresses of asymmetric synthesis of five and six membered rings promoted by squaramides. A handful of articles have been published by several research groups documenting asymmetric construction of five-and six-membered rings as part of interesting and complex molecular architectures. Different methodologies like conventional and formal cycloadditions or cascade reactions have been engineered through the assistance of chiral squaramides to fabricate the carbo-and heterocycles. This review also includes dual and cooperative catalytic system in which squaramide is one of the catalysts.

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Section: Synthesis Of Five‐ Membered Ringsmentioning

confidence: 99%

Squaramide Catalyzed Asymmetric Synthesis of Five‐ and Six‐Membered Rings

Biswas¹,

Ghosh

Shankhdhar

et al. 2021

Asian J Org Chem

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show abstract

“…Related work was reported in 2018 by Lin, Weng, Lu and coworkers using α-benzylidene chromanones, as well as the related tetralones and indanones as dipolarophiles (Scheme 25). [43] In this case, a new squaramide 12 derived from rosin and diaminocyclohexane was used as a bifunctional catalyst. Good results were obtained in all the studied cases.…”

Section: -Isothiocyanato Oxindoles As Formal Dipolesmentioning

confidence: 99%

Asymmetric Organocatalytic Synthesis of aza‐Spirocyclic Compounds from Isothiocyanates and Isocyanides

et al. 2021

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The spirocyclic motif is present in natural products, chiral ligands, and compounds of pharmacological interest. Isothiocyanates as well as isocyanides bearing electron-withdrawing groups in the α-position can be deprotonated and react as formal dipoles on account of the presence of a nucleophilic carbanion and an electrophilic atom in the isothiocyanate or isocyanide functional groups. In the last years a number of procedures involving the formal [3 + 2] cycloaddition reaction of isothiocyanates or isocyanides with cyclic compounds bearing electrophilic exocyclic double bonds have been developed for the enantioselective synthesis of aza-spirocyclic compounds. Among them, organocatalysis has played a predominant role in the development of asymmetric versions for these reactions. The synthesis of spirooxindoles by using this methodology has received especial attention, although other spirocyclic scaffolds are available depending on the structure of the dipolarophiles and the formal isothiocyanate and isocyanide dipoles.

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“…The high C−H acidity of 2‐indolones, which also have different functional groups at the C(3) atom, allows the use of these compounds in the synthesis of a wide range of spiro‐fused heterocycles catalyzed by squaramides [254] or other organic bases [255] . The formation of spirocyclic derivatives of indolone 233 by the reaction of 3‐hydroxyindolones 234 with dicyanoethylene 235 in the presence of squaramide 236 goes through the Michael reaction and the subsequent Pinner reaction.…”

Section: Syntheses Of Spiroheterocycles From 3‐alkylidene‐indol‐2‐onementioning

confidence: 99%

Advances in the Synthesis of Benzo‐Fused Spiro Nitrogen Heterocycles: New Approaches and Modification of Old Strategies

Гатауллин

2020

Helvetica Chimica Acta

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The review covers the results of studies published in the literature on the synthesis of spiro-linked heterocycles of the indole, quinoline, benzoxazine, benzothiazine, indenoquinoxaline, pyridopyrimidine, and acridine series. Possible approaches to the synthesis of spirocycles through a sequence of well-known Knoevenagel, Michael reactions, deamination cyclization of 1,2-dicarbonyl, CH-acid compounds, direct cycloaddition of activated olefins to isatins, 3-alkylideneindoles, 2-oxindoles, in situ generated azomethine ylides, indenoquinoxalines are analyzed. Attention is drawn to approaches to the preparation of spiro-fused compounds using reactions of intra-and intermolecular dearomatization of indoles. Recent advances in the synthesis of spiro-linked benzo heterocycles from derivatives of 2-olefin substituted anilines are summarized. The examples of the synthesis of spiro-fused heterocycles by means of metal complexes catalyzed decomposition of diazo compounds are given. Some syntheses of biologically active representatives are shown, as well as the use of transformations of spiroheterocycles in the preparation of other heterocycles.

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Highly efficient construction of chiral dispirocyclic oxindole/thiobutyrolactam/chromanone complexes through Michael/cyclization cascade reactions with a rosin-based squaramide catalyst

Cited by 28 publications

References 57 publications

Squaramide Catalyzed Asymmetric Synthesis of Five‐ and Six‐Membered Rings

Squaramide Catalyzed Asymmetric Synthesis of Five‐ and Six‐Membered Rings

Asymmetric Organocatalytic Synthesis of aza‐Spirocyclic Compounds from Isothiocyanates and Isocyanides

Advances in the Synthesis of Benzo‐Fused Spiro Nitrogen Heterocycles: New Approaches and Modification of Old Strategies

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