Kunda A. R. Sastry

Synthesis of arylboronic acids via the reaction of borane with arylmagnesium halides

Abstract The reaction of borane complexes with arylmagnesium halides produces the corresponding arylborohydrides in high yield. The arylborohydrides are readily hydrolyzed to the arylboronic acids. The syntheses are conveniently carried out in one pot. The reaction mechanism was clarified via a boron-11 NMR study.

Synthesis of Vinyl Bromides Via Reaction of Vinyl Boronic Acids with Sodium Bromide

Abstract Vinyl halides have proven to be useful synthetic intermediates.1,2 Recently, it was discovered that vinyl iodides are more stable to in-vivo deiodination than the corresponding alkyl iodides.3,4 This fact makes the vinyl halides potentially valuable in the design and syntheses of radiopharmaceuticals. Because of our interest in pharmaceutical design, we recently developed a synthesis of vinyl iodides in which vinyl boronic acids are allowed to react with sodium iodide in the presence of mild oxidizing agents.5 The method has been successfully applied to a variety of functionally substituted, physiologically active molecules including fatty acids and steroids.6 We now wish to report that vinyl bromides are readily synthesized via the reaction of vinyl boronic acids with sodium bromide in the presence of mild oxidizing agents such as N-chlorosuccinimide.

SYNTHESIS OF ARYL HALIDES via ORGANOBORANE CHEMISTRY

A method for the rapid synthesis of a variety of substituted aryl halides by the reaction of organoboranes with halide ions in the presence of chloramine-T is described in detail. The products were purified by column chromatography on silica gel using a mixture of petroleum ether-ethyl acetate as eluent.

Reaction of Organoboranes with iodine

Abstract The reaction of organoboranes with iodine is an efficient method for synthesizing alkyl iodides.1–3 Unfortunately the earlier methods employed sodium methoxide as a reactant which is a potential problem when the organoborane contians reactive functional groups. We recently reported that organoboranes readily react with iodine monochloride in the presence of sodium acetate, a mild base.4,5.

Synthesis of nitrogen-15-labelled primary amines via organoborane reactions

15 N-Labelled primary amines are readily snythesized via the reaction of organoboranes with 15N-enriched ammonium hydroxide; functionally substituted organic amines are efficently prepared via the new synthesis.

Synthesis of carbon-13 labelled carboxylic acids via organoborane reactions

13 C-Labelled carboxylic acids are readily synthesized via the reaction of organoboranes with 13C-enriched carbon monoxide; functionally substituted acids are efficiently prepared via a carbonylation–oxidation sequence.