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Isotopes have played an important role in chemistry, biology, and medicine. For the last three decades, we have focused on the use of organoboron compounds as precursors to isotopically labeled physiologically active reagents. During that period, we have successfully developed methods for incorporating short- and long-lived isotopes of carbon, nitrogen, oxygen, and the halogens using a variety of reactive organoboron precursors. In addition, labeling strategies employing polymer-supported organoboron derivatives were developed. In this report, we present a short overview focused on the evolution of radiolabeling techniques based on boron chemistry. [ABSTRACT FROM AUTHOR]

In the presence of boron trihalides, aryl aldehydes couple readily with allylmetals to afford haloallylated products. The reactions tolerate a variety of functional groups. Simple aqueous workup of haloallylation reactions, followed by treatment with 1,8- diazabicyclo[5.4.0]undec-7-ene, provides a straightforward route to synthetically useful (E)-1,3-dienes. The mild reaction conditions, readily available starting materials, and high stereoselectivity make this two-step (E)-1,3-diene synthesis quite attractive. [ABSTRACT FROM AUTHOR]

The synthetic potential of stereoselective, palladium-catalyzed hydro(het)arylation reactions of bi-, tri- and tetracyclic (hetero)alkenes in the presence of phospines and arsines as highly efficient ligands was studied. The mechanism of this reductive Heck reaction becomes more complex in the case of benzonorbornenes. Hydroarylation of diazabicyclo-[2.2.1]heptenes provides a stereoselective access to aryldiaminocyclopentanes. Electrondeficient arylpalladium complexes shift the reaction towards the product of a formal 1,2-hydrazidoarylation reaction of 1,3-cyclopentadiene by a stereoselective C-N cleavage. Due to steric reasons, rigid bicyclo[2.2.2]octenes react slower in hydroarylation reactions than the corresponding bicyclo[2.2.1]heptenes. The more flexible bicyclo[4.2.2]decene system already tends to undergo domino-Heck reactions, even under reductive conditions. When a tetracyclic cis-allylcyclopropane is carbopalladated in the presence of formates, the neighboring cyclopropane ring is attacked in the first reported example of a p,s domino-Heck reaction. [ABSTRACT FROM AUTHOR]

A novel boronated aminocyclobutanecarboxylic acid was synthesized for potential use in neutron capture therapy. The synthesis involves the preparation of tosylate 5, which was then converted to an amino acid using Bucherer-Strecker methodology. The molecule was modeled after the unnatural amino acid, 1-aminocyclobutane-1-carboxylic acid, which has shown high uptake in brain tumors. [ABSTRACT FROM AUTHOR]

The reaction of aryl aldehydes with allylsilanes in the presence of boron trihalides produces haloallylated products. Mechanistic details are presented. [ABSTRACT FROM AUTHOR]