Development of a second generation palladium-catalyzed cycloalkenylation and its application to bioactive natural product synthesis.

Development of a second generation palladium-catalyzed cycloalkenylation and its application to bioactive natural product synthesis.

Natural product communications (2013-08-29)

Masahiro Toyota

ABSTRACT

A novel palladium-catalyzed intramolecular oxidative alkylation of unactivated olefins is described. This protocol was devised to solve one of the drawbacks of the original palladium-catalyzed cycloalkenylation that we developed. We call this new procedure the 'second generation palladium-catalyzed cycloalkenylation'. This protocol has been applied to the total syntheses of cis-195A, trans-195A, boonein, scholareins A, C, D, and alpha-skytanthine.

MATERIALS

Product Number

Brand

Product Description

686468

Sigma-Aldrich

Palladium, nanopowder, <25 nm particle size (TEM), ≥99.5%

348678

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Palladium, foil, thickness 1.0 mm, 99.9% trace metals basis

348643

Sigma-Aldrich

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203998

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326666

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203939

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348694

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267112

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267120

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267082

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373206

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287474

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Palladium, foil, thickness 0.5 mm, 99.9% trace metals basis

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Palladium, microfoil, disks, 50mm, thinness 0.25μm, specific density 303.4μg/cm², permanent mylar 3.5μm support, 99.99%

GF52930762

Palladium, microfoil, disks, 10mm, thinness 0.5μm, specific density 303.4μg/cm², permanent mylar 3.5μm support, 99.99%

GF88212898

Palladium, foil, not light tested, 50x50mm, thickness 0.025mm, as rolled, 99.95%

GF10106457

Palladium, foil, not light tested, 100x100mm, thickness 0.008mm, 99.95%

GF77717526

Palladium, foil, not light tested, 25x25mm, thickness 0.0015mm, 99.95%

GF84888297

Palladium, microfoil, disks, 25mm, thinness 0.25μm, specific density 303.4μg/cm², permanent mylar 3.5μm support, 99.99%

GF03499016

Palladium, foil, not light tested, 50x50mm, thickness 0.03mm, as rolled, 99.95%

GF68272588

Palladium, rod, 25mm, diameter 6.0mm, 99.95%

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Palladium, foil, not light tested, 150x150mm, thickness 0.025mm, as rolled, 99.95%

GF26034230

Palladium, microfoil, disks, 10mm, thinness 0.25μm, specific density 303.4μg/cm², permanent mylar 3.5μm support, 99.99%

GF81049394

Palladium, foil, not light tested, 50x50mm, thickness 0.0025mm, 99.95%

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GF15900713

Palladium, microfoil, disks, 25mm, thinness 0.5μm, specific density 303.4μg/cm², permanent mylar 3.5μm support, 99.99%

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Palladium, microfoil, disks, 25mm, thinness 0.1μm, specific density 119.2μg/cm², permanent mylar 3.5μm support, 99.99%

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Palladium, rod, 50mm, diameter 2.0mm, 99.95%