Direct synthesis of pentafluoroethyl copper from pentafluoropropionate as an economical C2F5 source: application to pentafluoroethylation of arylboronic acids and aryl bromides.

Direct synthesis of pentafluoroethyl copper from pentafluoropropionate as an economical C2F5 source: application to pentafluoroethylation of arylboronic acids and aryl bromides.

Organic letters (2014-06-14)

Hiroki Serizawa, Kohsuke Aikawa, Koichi Mikami

ABSTRACT

The direct synthesis of pentafluoroethyl copper (CuC2F5) from a cuprate reagent and ethyl pentafluoropropionate as one of the most economical and useful pentafluoroethyl sources was accomplished. The advantages of this method are; all the reagents employed are low-cost and operationally simple, and the CuC2F5 reagent is prepared in virtually quantitative yield. Furthermore, the CuC2F5 reagent prepared was successfully applied to two types of pentafluoroethylations with arylboronic acids and aryl bromides to provide the pentafluoroethylated aromatic products in good-to-excellent yields, including large scale operations.

MATERIALS

Product Number

Brand

Product Description

207780

Sigma-Aldrich

Copper, powder, <75 μm, 99%

254177

Sigma-Aldrich

Copper, beads, 2-8 mm, 99.9995% trace metals basis

349151

Sigma-Aldrich

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

326410

Sigma-Aldrich

Copper, wire, diam. 0.64 mm, 99.995% trace metals basis

349216

Sigma-Aldrich

Copper, wire, diam. 1.0 mm, ≥99.9%

349224

Sigma-Aldrich

Copper, wire, diam. 2.0 mm, 99.999% trace metals basis

BCR058

Continuous cast copper (O), BCR^®, certified reference material, rod

326488

Sigma-Aldrich

Copper, beads, 2-8 mm, ≥99.99% trace metals basis

266744

Sigma-Aldrich

Copper, foil, thickness 1.0 mm, 99.999% trace metals basis

349208

Sigma-Aldrich

Copper, foil, thickness 0.025 mm, 99.98% trace metals basis

326429

Sigma-Aldrich

Copper, wire, diam. 0.25 mm, 99.999% trace metals basis

12816

Sigma-Aldrich

Copper, foil, ≥99.8% (complexometric)

61139

Sigma-Aldrich

Copper, turnings, purum p.a., ≥99.0%

GF83396627

Copper, insulated wire, 20m, conductor diameter 1.0mm, insulation thickness 0.25mm, PTFE (polytetrafluoroethylene) insulation

GF71474249

Copper - O.F.H.C., foil, 300x300mm, thickness 0.1mm, half hard, 99.95+%

GF37945569

Copper, insulated wire, 1m, conductor diameter 0.45mm, insulation thickness 0.25mm, PTFE (polytetrafluoroethylene) insulation

GF47876541

Copper - O.F.H.C., tube, 500mm, outside diameter 10mm, inside diameter 8mm, wall thickness 1.0mm, 99.95+%

GF53960283

Copper - O.F.H.C., foil, 150x150mm, thickness 0.25mm, annealed, 99.95+%

GF50574911

Copper - O.F.H.C., foil, 0.5m coil, thickness 0.05mm, coil width 300mm, half hard, 99.95+%

GF99527844

Copper - O.F.H.C., foil, 10m coil, thickness 0.05mm, coil width 10mm, annealed, 99.95+%

GF94180293

Copper - O.F.H.C., foil, 0.5m coil, thickness 0.05mm, hard, 99.95+%

GF87534917

Copper, insulated wire, 50m, conductor diameter 0.1mm, insulation thickness 0.015mm, 10-30 micron polyesterimide insulation, 99.9%

GF84488462

Copper, insulated wire, 5m, conductor diameter 0.5mm, insulation thickness 0.06mm, polyimide insulation

GF38551136

Copper - O.F.H.C., foil, 0.5m coil, thickness 0.1mm, hard, 99.95+%

GF88218276

Copper, insulated wire, 250m, conductor diameter 0.05mm, insulation thickness 0.002mm, 2 micron polyesterimide insulation, 99.9%

GF08487456

Copper - O.F.H.C., foil, 300x300mm, thickness 0.1mm, hard, 99.95+%

GF04898357

Copper, insulated wire, 20m, conductor diameter 0.125mm, insulation thickness 0.01mm, polyimide insulation, 99.99%

GF61610699

Copper, insulated wire, 100m, conductor diameter 0.24mm, insulation thickness 0.25mm, PTFE (polytetrafluoroethylene) insulation

GF82273057

Copper, insulated wire, 5m, conductor diameter 0.7mm, insulation thickness 0.01mm, polyurethane insulation

GF13809528

Copper - O.F.H.C., foil, 25x25mm, thickness 0.25mm, annealed, 99.95+%