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

357456

Sigma-Aldrich

Copper, powder (dendritic), <45 μm, 99.7% trace metals basis

349178

Sigma-Aldrich

Copper, foil, thickness 0.25 mm, 99.98% trace metals basis

266086

Sigma-Aldrich

Copper, powder, <425 μm, 99.5% trace metals basis

BCR054R

Copper (O), BCR^®, certified reference material, rod

326453

Sigma-Aldrich

Copper, powder (spheroidal), 10-25 μm, 98%

223409

Sigma-Aldrich

Copper, shot, −3-+14 mesh, 99%

290920

Sigma-Aldrich

Ethyl pentafluoropropionate, 98%

311405

Sigma-Aldrich

Copper, ACS reagent, granular, 10-40 mesh, ≥99.90%

203122

Sigma-Aldrich

Copper, powder, 99.99% trace metals basis

IRMM522A

Copper, IRMM^®, certified reference material, 0.1 mm foil

IRMM522C

Copper, IRMM^®, certified reference material, 0.5 mm wire

BCR017B

Copper (S, P), BCR^®, certified reference material, chips

GF76929890

Copper - O.F.H.C., foil, 8mm disks, thickness 0.025mm, hard, 99.95+%

GF22027799

Copper, tube, 1000mm, outside diameter 6.35mm, inside diameter 4.93mm, wall thickness 0.71mm, as drawn, 99.9%

GF54651146

Copper, tube, 1000mm, outside diameter 0.25mm, inside diameter 0.05mm, wall thickness 0.1mm, as drawn, 99.9%

GF14973060

Copper, tube, 100mm, outside diameter 10.4mm, inside diameter 10mm, wall thickness 0.2mm, as drawn, 99.9%

GF22915436

Copper, tube, 1000mm, outside diameter 2.0mm, inside diameter 1.6mm, wall thickness 0.2mm, as drawn, 99.9%

GF16408425

Copper, tube, 1000mm, outside diameter 2.5mm, inside diameter 1.9mm, wall thickness 0.3mm, as drawn, 99.9%

GF29372441

Copper, sphere, 100pcs, diameter 1.0mm, precision sphere grade 200

GF50300817

Copper - O.F.H.C., foil, not light tested, 100x100mm, thickness 0.006mm, hard, 99.95+%

GF85331549

Copper - O.F.H.C., foil, 8mm disks, thickness 0.25mm, annealed, 99.95+%

GF43598784

Copper - O.F.H.C., rod, 100mm, diameter 38.1mm, as drawn, 99.95+%

GF96136296

Copper - O.F.H.C., foil, 8mm disks, thickness 0.075mm, half hard, 99.95+%

GF86291972

Copper - O.F.H.C., foil, light tested, 50x50mm, thickness 0.05mm, annealed, 99.95+%

GF86247524

Copper - O.F.H.C., foil, light tested, 100x100mm, thickness 0.025mm, hard, 99.95+%

GF87039388

Copper - O.F.H.C., foil, 6mm disks, thickness 0.25mm, annealed, 99.95+%

GF92987274

Copper - O.F.H.C., foil, 8mm disks, thickness 0.05mm, hard, 99.95+%

GF64538556

Copper - O.F.H.C., foil, not light tested, 50x50mm, thickness 0.006mm, hard, 99.95+%

GF80941158

Copper - O.F.H.C., foil, light tested, 150x150mm, thickness 0.025mm, hard, 99.95+%

GF62890678

Copper - O.F.H.C., rod, 100mm, diameter 12.7mm, as drawn, 99.95+%