New Boronic Acid Surrogates for Researchers

Scientists hold bottles of recently commercialized N methyliminodiacetic (MIDA) products from Sigma-Aldrich. (Source: Sigma Aldrich)

Sigma-Aldrich says it has signed an exclusive licensing agreement with the University of Illinois at Urbana- Champaign allowing the company to offer research quantities of new boronic acid surrogates for use in Suzuki-Miyaura coupling to researchers worldwide. Under the terms of the agreement, Sigma-Aldrich can also satisfy commercial-scale requests for these surrogates from its manufacturing customers.

Developed by Professor Martin Burke and co-workers, the technology has implications for drug discovery, where the ability to quickly create large sets of related small molecules for use in screening is critical.

The advancement relies on the use of a simple, low-cost, and environmentallyfriendly ligand (N-methyliminodiacetic acid or MIDA) that reversibly modulates boronic acids toward cross-coupling. The MIDA-ligated boronic acid building blocks can be used to construct target molecules using a single cross-coupling reaction in an iterative process, in a fashion resembling peptide synthesis. Complex bioactive molecules can also be efficiently constructed, as demonstrated in recent publications from the Burke research group in 2007 and 2008.

"In collaboration with the Burke group, our R&D groups have actively developed the syntheses of dozens of MIDA boronic acid derivatives, many of which will be available globally in the coming weeks. We expect to offer a broad set of these 'off-theshelf' MIDA synthons, which will enable chemists to rapidly assemble complex chemical architectures using a single palladium-catalyzed reaction," says Nate Wallock, chemistry technology transfer Scientists hold bottles of recently commercialized N-methyliminodiacetic (MIDA) products from Sigma-Aldrich. (Source: Sigma-Aldrich) manager at Sigma-Aldrich.

In addition to applications in iterative cross-coupling, MIDA-protected boronic acids (i.e., MIDA boronate esters) have enhanced shelf lives relative to the free boronic acids that often suffer from limited bench top stability. Unlike other boronic acid derivatives that may exhibit reduced reactivity relative to their boronic acid counterparts, the MIDA boronate esters are cleaved under exceptionally mild conditions to release the coupling-active boronic acid.