Nickel-catalyzed intramolecular [3 + 2 + 2] cycloadditions of alkylidenecyclopropanes. A straightforward entry to fused 6,7,5-tricyclic systems.

Nickel-catalyzed intramolecular [3 + 2 + 2] cycloadditions of alkylidenecyclopropanes. A straightforward entry to fused 6,7,5-tricyclic systems.

Organic letters (2014-09-19)

Lucía Saya, Israel Fernández, Fernando López, José L Mascareñas

ABSTRACT

A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloaddition occurring via a proximal cleavage of the cyclopropane and makes it possible to build relevant 6,7,5-tricyclic frameworks in a single-pot reaction. Importantly, the reaction outcome is highly dependent on the characteristics of the nickel ligands.

MATERIALS

Product Number

Brand

Product Description

267074

Sigma-Aldrich

Nickel, rod, diam. 6.35 mm, ≥99.99% trace metals basis

577995

Sigma-Aldrich

Nickel, nanopowder, <100 nm avg. part. size, ≥99% trace metals basis

357553

Sigma-Aldrich

Nickel, foil, thickness 0.5 mm, 99.98% trace metals basis

357626

Sigma-Aldrich

Nickel, wire, diam. 0.5 mm, ≥99.9% trace metals basis

357588

Sigma-Aldrich

Nickel, foil, thickness 0.1 mm, 99.98% trace metals basis

GF06171476

Nickel, foil, 1m coil, thickness 0.05mm, 99.9%

GF07926037

Nickel, rod, 50mm, diameter 40mm, 99%

GF43660313

Nickel, tube, 100mm, outside diameter 2.0mm, inside diameter 1.6mm, wall thickness 0.2mm, hard, 99.5%

GF51193818

Nickel, rod, 500mm, diameter 3.3mm, 99.99+%

GF38105388

Nickel, tube, 200mm, outside diameter 7.11mm, inside diameter 6.57mm, wall thickness 0.27mm, hard, 99.5%

GF23066197

Nickel, tube, 200mm, outside diameter 0.8mm, inside diameter 0.64mm, wall thickness 0.08mm, as drawn, 99.5%

GF98733314

Nickel, tube, 100mm, outside diameter 0.8mm, inside diameter 0.5mm, wall thickness 0.15mm, as drawn, 99.5%

GF29576010

Nickel, rod, 100mm, diameter 16mm, 99.99+%

GF59535557

Nickel, foil, 1m coil, thickness 0.3mm, coil width 1mm, annealed, 99%

GF17568861

Nickel, tube, 1000mm, outside diameter 4.5mm, inside diameter 3.154mm, wall thickness 0.673mm, hard, 99.5%

GF53239237

Nickel, foil, 1m coil, thickness 0.004mm, hard, 99%

GF97611048

Nickel, foil, 1m coil, thickness 0.05mm, annealed, 99%

GF42115115

Nickel, foil, 15mm disks, thickness 0.5mm, as rolled, 99.99+%

GF73640505

Nickel, foil, 15mm disks, thickness 0.075mm, annealed, 99%

GF47594144

Nickel, tube, 1000mm, outside diameter 0.8mm, inside diameter 0.3mm, wall thickness 0.25mm, as drawn, 99.5%

GF61415030

Nickel, tube, 200mm, outside diameter 2.4mm, inside diameter 2.248mm, wall thickness 0.076mm, hard, 99.5%

GF85768622

Nickel, tube, 100mm, outside diameter 8.4mm, inside diameter 8.15mm, wall thickness 0.125mm, hard, 99.5%

GF31955171

Nickel, tube, 1000mm, outside diameter 1.0mm, inside diameter 0.2mm, wall thickness 0.4mm, hard, 99.5%

GF65581184

Nickel, tube, 100mm, outside diameter 0.8mm, inside diameter 0.3mm, wall thickness 0.25mm, as drawn, 99.5%

GF04485944

Nickel, foil, 1m coil, thickness 0.20mm, annealed, 99%

GF85930623

Nickel, foil, 1m coil, thickness 0.025mm, annealed, 99%

GF38000674

Nickel, foil, 15mm disks, thickness 0.30mm, as rolled, 99.98%

GF99673802

Nickel, foil, 25mm disks, thickness 0.05mm, as rolled, 99.99+%

GF11598194

Nickel, rod, 100mm, diameter 12.7mm, 99.98%

GF85397192

Nickel, foil, 1m coil, thickness 0.3mm, annealed, 99%