Seung-Hoi Kim

Direct formation of organomanganese bromides using rieke manganese

Abstract The direct formation of organomanganese bromides can be accomplished under mild conditions from the direct oxidative addition of Rieke manganese to alkyl and thienyl bromides.

Preparation and coupling reaction of thienylmanganese bromides

Abstract 3-Thienylmanganese bromide, 3-bromo-4-thienylmanganese bromide and 4-substituted 3-thienylmanganese bromides were prepared from the reactions of Rieke manganese with 3-bromothiophene, 3,4-dibromothiophene and 4-substituted 3-bromothiophenes, respectively. The resulting thienylmanganese bromides underwent cross-coupling reactions under mild reaction conditions.

Direct Preparation of Arylmanganese Bromides Using Active Manganese

Abstract Arylmanganese compounds were easily prepared via the direct oxidative addition of Rieke manganese to aryl bromides under mild conditions. The resulting organomanganese reagents undergo coupling reaction with acid chlorides to give the corresponding ketones in moderate yields.

A new synthetic protocol for the direct preparation of organomanganese reagents; organomanganese tosylates and mesylates

Abstract A new synthetic route to organomanganese sulfonate reagents has been developed. These useful reagents can be readily prepared via direct oxidative addition of highly reactive manganese to carbonoxygen bonds of the corresponding tosylates and mesylates under mild conditions.

5-Substituted-2-furaldehydes: a synthetic protocol utilizing an organozinc route.

Facile synthetic routes for the preparation of a wide range of 5-substituted 2-furaldehydes have been revealed. They were accomplished through either Pd-catalyzed cross-coupling reaction of various aryl- and heteroarylzinc halides with 5-bromo-2-furaldehyde or utilization of a new organozinc reagent, 5-(1,3-dioxolan-2-yl)-2-furanylzinc bromide, which was easily prepared by the direct insertion of highly active zinc to 2-(5-bromofuran-2-yl-1,3-dioxolane. Of special note is the uniqueness of using a new organozinc reagent, representing a first example of the direct synthesis of the corresponding organozinc halide. The subsequent coupling reactions in various types of reaction conditions led to the formation of somewhat different furan derivatives. It is also of significance that all of the cross-coupling reactions were carried out under mild conditions.