Burke boronates

Burke boronates can be conveniently prepared from the corresponding boronic ac 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 42, Springer-Verlag Berlin Heidelberg 2009 

A wide range of selective couplings can be performed at the halide terminus of a B-protected haloboronic acid. 

Small molecule natural products can be prepared via iterative cross-coupling with B-protected haloboronic acids. 

Burke boronates are stable to a wide range of synthetic reagents, including acids, non-aqueous bases, oxidants, reductants, electrophiles, and soft nucleophiles. This reagent compatibility enables multistep synthesis of complex boranes from simple boron-containing starting materials. 

Alternatively, many of these building blocks are now commercially available. Example 1  

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOI 10.1007/978-3-319-03979-4 47, Springer International Publishing Switzerland 2014 

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Burke boronates can be hydrolyzed in situ under aqueous basic coupling conditions, as evidenced by fliis synthesis of the complex polyene skeleton of amphotericin B. 

Burke boronates can be used directly in cross-couplings as shelf-stable suno tes for unstable boronic acids via slow-release cross-coupling. 

The MIDA-protected boronate esters developed by Burke and coworkers allow iterative Suzuki cross coupling reactions under mild conditions to give polyenes [64,65]. The MIDA-protected boronate esters are stable and easily handled, and deprotection occurs readily at room temperature under mild basic conditions to provide the corresponding boronic acids. 

Burk, P. and Kutsar, M. (2005) Comparative calculations of complexation enthalpies between Lewis bases and boron trifluoride. Proc. Est. Acad. ScL, Chem., 54, 154-164. 

Coupling partner for Suzuki reaction can be boronic acids, their esters, trifluoroborates, or boranes (in particular derived from 9-borabicyclononane (9-BBN) jV-methylimino diacetic acid (MIDA) boronates (Scheme 5-57) developed by Burke pose a very useful alternative to boronic acids, as they are stable under some different palladium-catalysis e.g., Stille couplings) and can be "switched on" by nucleophiles. An application is shown in the following Experimental Procedure. ... 

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