Total synthesis of (±)-lycoricidine

Ohta, Shunsaku; Kimoto, Shoshichiro

doi:10.1016/s0040-4039(00)75100-8

Cited by 59 publications

(19 citation statements)

References 8 publications

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“…273-275°C. 1 (14), 115 (9), 114 (14), 109 (12). Compound 13b exhibits spectral and analytical data in accordance with that in ref.…”

Section: -(Pyridin-2-yl)isoquinolin-1-(2h)-one (9a)supporting

confidence: 84%

“…the base-promoted condensation reactions with 2-(bromomethyl)benzonitrile to the synthesis of indolo(3,2-c)iso-quinolinone], [11] the transformation of isocoumarins by primary amines, [12] double metalation of an N-propenyl-2-methyl benzamide to give a cyclocondensation reaction with DMF, [13] S N Ar reactions from 2-chlorobenzonitriles with β-keto esters followed by cyclization in acid conditions, [14] and intramolecular Diels-Alder reactions. [2] Recently, the synthesis of isoquinolinones has been improved by using transition-metal catalysts.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO

2006

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“…273-275°C. 1 (14), 115 (9), 114 (14), 109 (12). Compound 13b exhibits spectral and analytical data in accordance with that in ref.…”

Section: -(Pyridin-2-yl)isoquinolin-1-(2h)-one (9a)supporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO

2006

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“…Substituted phenethyl isocyanates undergo cyclization to lactams when treated with BF3.Et20 [65]. Vinyl ether epoxides (Eq.…”

Section: Cyclizationsmentioning

confidence: 99%

Achiral B(III) Lewis Acids

Ishihara¹

2000

Lewis Acids in Organic Synthesis

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The classical boron Lewis acids, BX3, RBX2 and R2BX (X = F, C1, Br, I, OTf) are now popular tools in organic synthesis. B(II1) can act as a Lewis acid because there is an empty p-orbital on the boron. Enthalpy values indicate that when pyridine is the reference base, the Lewis acidity of Group IIIB halides increase in the order A1X3 > BX3 > GaX3. The Lewis acidity of BX3 generally increases in the order fluoride < chloride < bromide < iodide, i.e. the exact reverse of the order expected on the basis of the relative o-donor strengths of the halide anions. The main reason for this anomaly is that in these BX3 compounds, the B-X bonds contain a n-component which is formed by overlap of a filled p-orbital on the halogen with the empty p-orbital on the boron. Because the latter orbital is used to form an o-bond when BX3 coordinates with a Lewis base, this n-component is completely destroyed by complex formation. The strength of the n-component now increases in the order iodide < bromide < chloride < fluoride, i.e. the amount of n-bond energy that is lost on complex formation increases as the atomic weight of the halogen decreases. Evidently, as far as the extent of complex formation is concerned, this is a more important factor than the corresponding decrease in the o-donor strength of the halogen.The BF3 and BC13 complexes of diethyl ether are less stable than those of dimethyl ether, and the same order of stability is observed for the complexes of diethyl and dimethyl sulfides. As expected, steric interaction decreases as the distance between the metal and ligand atom is increased. Thus, it decreases when the metal atom is changed from boron to aluminum, or when the ligand atom is changed from oxygen to sulfur.The major applications of BX3 Lewis acids in organic synthesis include dealkylation of ethers, condensation reactions, and as a catalyst for Friedel-Crafts-type reactions and other acid-related chemistry. In general, these are used stoichiometrically in organic transformations under anhydrous conditions, because the presence of even a small amount of water causes rapid decomposition or deactivation of the promoters. To obviate some of these inherent problems, the potential of arylboron compounds, Ar,B(OH),-3 ( n = 1-3), bearing electron-withdrawing aromatic groups as a new class of boron catalysts has recently been demonstrated. For example, tris(pentafluor0phenyl)borane, B(C6F5)3, is a convenient, commercially available Lewis acid of strength comparable with that of BF3, but without the problems associated with reactive B-F bonds. Although its primary commercial application is as a co-catalyst in metallocene-mediated olefin polymerization, its potential as a Lewis acid catalyst for organic transformations is now recognized as being much more extensive. Diarylborinic acids and arylboronic acids bearing electron-withdrawing aromatic groups are also highly effective Lewis acid catalysts.This chapter focuses on the synthetic applications of BX3 as Lewis acids and the organic transformations catalyzed by arylboron...

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“…The latter method has been used in the synthesis of (�)-licoricidin (Beccalli et al, 2007), narciclasine (Khaldi et al, 1995), (þ)-deoxypancratistatin (Ohta & Kimoto, 1975) and the benzophenanthridine alkaloid nitidine (Minami et al, 1995). As majority of the natural isocoumarins being of polyketide origin possess a C-3 alkyl, alkenyl or aryl substituent consequently, a variety of methodologies are available for rapid access to these bioactive heterocycles (Napolitano, 1997).…”

Section: Introductionmentioning

confidence: 99%

An efficient total synthesis of ruprechstyril fromRuprechtia tangarana

Saeed

2013

Natural Product Research

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A short total synthesis of natural isocarbostyril ruprechstyril (3-n-pentyl-6-methoxy-8-hydroxy-1(2H)-isoquinolinone) isolated from Ruprechtia tangarana is reported. 6,8-Dimethoxy-3-pentylisocoumarin obtained by condensation of 3,5-dimethoxyhomophthalic anhydride with hexanoyl chloride was smoothly converted to O-methylruprechstyril by refluxing with methanamide. Regioselective demethylation of the latter using anhydrous aluminium chloride in dichloromethane furnished the ruprechstyril. Complete demethylation to give (6-desmethoxyruprechstyril) was achieved using same reagent in ethanethiol.

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Total synthesis of (±)-lycoricidine

Cited by 59 publications

References 8 publications

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO

Achiral B(III) Lewis Acids

An efficient total synthesis of ruprechstyril fromRuprechtia tangarana

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Total synthesis of (±)-lycoricidine

Cited by 59 publications

References 8 publications

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by SRN1 Reactions in DMSO

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by SRN1 Reactions in DMSO

Achiral B(III) Lewis Acids

An efficient total synthesis of ruprechstyril fromRuprechtia tangarana

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Product

Resources

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One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO

One‐Pot Synthesis of 3‐Substituted Isoquinolin‐1‐(2H)‐ones and Fused Isoquinolin‐1‐(2H)‐ones by S_RN1 Reactions in DMSO