Mechanism of Cu-Catalyzed Aryl Boronic Acid Halodeboronation Using Electrophilic Halogen: Development of a Base-Catalyzed Iododeboronation for Radiolabeling Applications

Abstract

An investigation into the mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen reagents is reported. Evidence is provided to show that this takes place via a boronate-driven ipso-substitution pathway and that Cu is not required for these processes to operate: general Lewis base catalysis is operational. This in turn allows the rational development of a general, simple, and effective base-catalyzed halodeboronation that is amenable to the preparation of 125 I-labeled products for SPECT applications.

Photoinduced Acetylation of Anilines under Aqueous and Catalyst-Free Conditions

“…84 mg, 76% General Procedure C (70 mg, 63% General Procedure D), light yellow oil (PE/EA 99:1 (v/v)). This compound is known, and the data reported here are consistent with the literature …”

Recent Advances in Synthetic Methods for Radioiodination

“…In 2019, iododeboronation from boronic acids was reinvestigated by the Sutherland and Watson groups (Scheme ). In this work, the role and positive contribution of a Lewis base was clearly evidenced. Thus, using NCS as an oxidant and a catalytic amount of KOAc to promote in situ formation of a boronate, the radioiodination of a variety of arenes bearing electron-donating or -withdrawing groups was achieved with RCYs between 49 and 99%.…”

Copper‐Catalyzed Cross‐Coupling of Benzylic Bromides with Arylboronic Acids: Synthesis of Diarylalkanes and Preliminary Antifungal Evaluation Against Magnaporthe Grisea

“…Thus, rigorous drying of the solvent and reagents was not necessary. Control screening disclosed that no expected product could be detected in the absence of ligand, copper catalyst or base, showing that this is not base‐assisted ipso ‐substitution process and undergoes different mechanism from Prof. Tang's report …”