Enantioselective Synthesis of (+)-Coerulescine by a Phase-Transfer Catalytic Allylation of Diphenylmethyl tert-Butyl α-(2-Nitrophenyl)Malonate

Lee, Sangki; Yang, Jewon; Yang, Sehun; Lee, Geumwoo; Oh, Dayoung; Ha, Min Woo; Hong, Suckchang; Park, Hyeung‐geun

doi:10.3389/fchem.2020.577371

Cited by 5 publications

(3 citation statements)

References 15 publications

(21 reference statements)

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“…To optimize the substrate among 3 – 7 , we examined the chemical yields and enantioselectivity of PTC α-benzylation under previously reported PTC conditions ( Hong et al, 2013 ; Lee et al, 2020 ). PTC α-benzylation was carried out with benzyl bromide (5.0 equiv.)…”

Section: Resultsmentioning

confidence: 99%

“…The resulting chiral α,α-dialkylmalonates could be selectively modified to chiral malonic monoacids by catalytic hydrogenation. The monoacids were converted to versatile building blocks and successfully applied to the total synthesis of (−)-horsfiline and (+)-coerulescine ( Hong et al, 2013 ; Lee et al, 2020 ). However, selective conversion to monoacids was not successful under acidic and basic conditions.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of chiral malonates by α-alkylation of 2,2-diphenylethyl tert-butyl malonates via enantioselective phase-transfer catalysis

Guo

Sagong

et al. 2023

Front. Chem.

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An efficient synthetic approach for chiral malonates was established via enantioselective phase transfer catalysis. The α-alkylation of 2,2-diphenylethyl tert-butyl α-methylmalonates with (S,S)-3,4,5-trifluorophenyl-NAS bromide as a phase-transfer catalyst under phase-transfer catalytic conditions successfully produced corresponding α-methyl-α-alkylmalonates; these compounds are versatile chiral building blocks containing a quaternary carbon center in high chemical yields (up to 99%) with excellent enantioselectivities (up to 98% ee). α,α-Dialkylmalonates were selectively hydrolyzed to the corresponding chiral malonic monoacids under basic (KOH/MeOH) and acidic conditions (TFA/CH2Cl2), showing the practicality of the method.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of chiral malonates by α-alkylation of 2,2-diphenylethyl tert-butyl malonates via enantioselective phase-transfer catalysis

Guo

Sagong

et al. 2023

Front. Chem.

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“…The spirooxindole class of bio-heterocycles are identified as privileged molecules and construct the core structural unit in several naturally occurring alkaloids such as horsfiline 1 [ 9 , 10 ], coerulescine 2 [ 11 , 12 ], marcfortine B 3 [ 13 ], spirotryprostatin A 4 and B 5 [ 14 , 15 ], elacomine 6 [ 16 ], formosanine 7 [ 17 ], pteropodine 8 [ 18 ], alstonisine 9 [ 19 ], rychnophyilline 10 [ 20 ], strychnofoline 11 [ 21 ], spirobrassinin 12 [ 22 ], mitraphylline 13 [ 23 ], notoamide A 14 [ 24 ], etc. ( Figure 1 ).…”

Section: Introductionmentioning

confidence: 99%

Natural-Product-Inspired Microwave-Assisted Synthesis of Novel Spirooxindoles as Antileishmanial Agents: Synthesis, Stereochemical Assignment, Bioevaluation, SAR, and Molecular Docking Studies

Sahu,

Sharma,

Suhas

et al. 2023

Molecules

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Leishmaniasis is a neglected tropical disease, and there is an emerging need for the development of effective drugs to treat it. To identify novel compounds with antileishmanial properties, a novel series of functionalized spiro[indoline-3,2′-pyrrolidin]-2-one/spiro[indoline-3,3′-pyrrolizin]-2-one 23a–f, 24a–f, and 25a–g were prepared from natural-product-inspired pharmaceutically privileged bioactive sub-structures, i.e., isatins 20a–h, various substituted chalcones 21a–f, and 22a–c amino acids, via 1,3-dipolar cycloaddition reactions in MeOH at 80 °C using a microwave-assisted approach. Compared to traditional methods, microwave-assisted synthesis produces higher yields and better quality, and it takes less time. We report here the in vitro antileishmanial activity against Leishmania donovani and SAR studies. The analogues 24a, 24e, 24f, and 25d were found to be the most active compounds of the series and showed IC50 values of 2.43 µM, 0.96 µM, 1.62 µM, and 3.55 µM, respectively, compared to the standard reference drug Amphotericin B (IC50 = 0.060 µM). All compounds were assessed for Leishmania DNA topoisomerase type IB inhibition activity using the standard drug Camptothecin, and 24a, 24e, 24f, and 25d showed potential results. In order to further validate the experimental results and gain a deeper understanding of the binding manner of such compounds, molecular docking studies were also performed. The stereochemistry of the novel functionalized spirooxindole derivatives was confirmed by single-crystal X-ray crystallography studies.

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“K‐synthesis”: Recent advancements in natural product synthesis enabled by unique methods and strategies development in Korea

Han

2022

Bulletin Korean Chem Soc

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Natural product synthesis has lain at the heart of organic chemistry. Complex structures of natural products have inspired chemists to develop new methods and strategies. The utility and robustness of newly developed methodologies have been tested by their application into total synthesis. With the necessity to establish a solid health-related and biomedical Korean industrial ecosystem, a historically belittled sector when compared to well-invested manufacturing and electronics industries in Korea, there has been enormous recent progress in the Korean organic chemical research. Accordingly, impressive syntheses of complex secondary metabolites that feature unique tactics and ingenious strategies have been reported by synthetic organic chemists in Korea. Herein, recent advancements (mostly after 2010) in natural product synthesis from Korea are depicted. Representative accomplishments from researchers in Korea are presented with an emphasis on unique methods and strategies that are utilized into their synthetic approaches.

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Enantioselective Synthesis of (+)-Coerulescine by a Phase-Transfer Catalytic Allylation of Diphenylmethyl tert-Butyl α-(2-Nitrophenyl)Malonate

Cited by 5 publications

References 15 publications

Synthesis of chiral malonates by α-alkylation of 2,2-diphenylethyl tert-butyl malonates via enantioselective phase-transfer catalysis

Synthesis of chiral malonates by α-alkylation of 2,2-diphenylethyl tert-butyl malonates via enantioselective phase-transfer catalysis

Natural-Product-Inspired Microwave-Assisted Synthesis of Novel Spirooxindoles as Antileishmanial Agents: Synthesis, Stereochemical Assignment, Bioevaluation, SAR, and Molecular Docking Studies

“K‐synthesis”: Recent advancements in natural product synthesis enabled by unique methods and strategies development in Korea

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