Skip to Content

Regioselective functionalization of the oxazole scaffold using TMP-bases of Mg and Zn.

Regioselective functionalization of the oxazole scaffold using TMP-bases of Mg and Zn.

Organic letters (2013-11-20)

Diana Haas, Marc Mosrin, Paul Knochel

ABSTRACT

A general method for the synthesis of 2,4,5-trisubstituted oxazoles has been developed. Starting from commercially available oxazole, successive metalations using TMPMgCl·LiCl or TMPZnCl·LiCl led to the corresponding magnesiated or zincated species which were stable toward ring fragmentation. Furthermore, they readily reacted with various electrophiles, such as aryl and allylic halides, acid chlorides, TMSCl, and TMS-CN, providing highly functionalized oxazoles.

MATERIALS

Product Number

Brand

Product Description

Sigma-Aldrich

Lithium, granular, 4-10 mesh particle size, high sodium, 99% (metals basis)

Sigma-Aldrich

Lithium, ribbon, thickness × W 0.38 mm × 23 mm, 99.9% trace metals basis

Sigma-Aldrich

Lithium, ribbon, thickness × W 0.75 mm × 45 mm, 99.9% trace metals basis

Sigma-Aldrich

Lithium, wire, diam. 3.2 mm, in mineral oil, ≥98%

Sigma-Aldrich

Lithium, ribbon, thickness × W 0.75 mm × 19 mm, 99.9% trace metals basis

Sigma-Aldrich

Lithium, wire (in mineral oil), diam. 3.2 mm, 99.9% trace metals basis

Sigma-Aldrich

Lithium, granular, 99% trace metals basis

Sigma-Aldrich

Lithium, rod, diam. 12.7 mm, 99.9% trace metals basis

Sigma-Aldrich

Lithium, ribbon, thickness × W 1.5 mm × 100 mm, 99.9% trace metals basis

Sigma-Aldrich

Magnesium, in a Sure/Seal^™ bottle, turnings, anhydrous tetrahydrofuran 37.5 mmol

Sigma-Aldrich

Magnesium, 20-230 mesh, reagent grade, 98%

Sigma-Aldrich

Magnesium, in a Sure/Seal^™ bottle, turnings, 37.5 mmol

Sigma-Aldrich

Magnesium preparation, Highly Reactive Rieke^® Metal, suspension, 2.5 g in THF

Sigma-Aldrich

Magnesium, grit, ≥99.0% (KT)

Sigma-Aldrich

Magnesium, turnings, 5-25 mm, 99.95% trace metals basis

Sigma-Aldrich

Magnesium, ribbon, ≥99.0% Mg basis

Sigma-Aldrich

Magnesium, powder, ≥99%

Sigma-Aldrich

Magnesium, rod, diam. 6 mm, ≥99.9% trace metals basis

Sigma-Aldrich

Magnesium, wire, 127 μm diameter, 99.9% trace metals basis

Sigma-Aldrich

Magnesium, dendritic pieces, purified by distillation, 99.998% trace metals basis

Sigma-Aldrich

Magnesium, ReagentPlus^®, ribbon, ≥99% trace metals basis

Sigma-Aldrich

Magnesium, purum, for Grignard reactions, ≥99.5%, turnings

Sigma-Aldrich

Magnesium, turnings, reagent grade, 98%

Sigma-Aldrich

Magnesium, chips, 6-35 mesh, 99.98% trace metals basis