SYNTHESIS OF PHENYLACETYL MIDA BORONATES BY OXIDATIVE CLEAVAGE OF VICINAL DIOLS

Multistep synthesis of complex boronic acids from simple MIDA boronates.

Due to its sensitivity to most synthetic reagents, it is typically necessary to introduce the boronic acid functional group just prior to its utilization. Overcoming this important limitation, we herein report that air- and chromatographically stable MIDA boronates are compatible with a wide range of common reagents which enables the multistep synthesis of complex boronic acid building blocks f...

Oxidative cleavage of vicinal diols: IBX can do what Dess-Martin periodinane (DMP) can.

The fact that IBX exhibits reactivity akin to DMP is demonstrated from the results observed with strained and sterically hindered syn 1,2-diols, which undergo oxidative cleavage via a 12-I-5 spirobicyclic periodinane. The use of TFA, a protonating solvent, promotes the formation of the 12-I-5 intermediate for 1,2-diols of all types (sec,sec, sec,tert and tert,tert), leading to efficient oxidati...

Tandem Cycloisomerization/Suzuki Coupling of Arylethynyl MIDA Boronates.

A tandem gold-catalyzed cycloisomerization/Suzuki cross coupling sequence involving arylethynyl-N-methyliminodiacetic acid boronates is described. Combining the mildness of homogeneous gold catalysis with the versatility of N-methyliminodiacetic acid (MIDA) boronates, this tandem two-step method enables the rapid assembly of various aryl-substituted heterocycles without having to isolate or pur...

Oxidative Difunctionalization of Alkenyl MIDA Boronates: A Versatile Platform for Halogenated and Trifluoromethylated α-Boryl Ketones.

The synthesis of halogenated and trifluoromethylated α-boryl ketones via a one-pot oxidative difunctionalization of alkenyl MIDA boronates is reported. These novel densely functionalized organoborons bearing synthetically and functionally valuable carbonyl, halogen/CF3 and boronate moieties within the same molecule are synthetically challenging for the chemist, but have great synthetic potentia...

Oxidative Heck Reactions using Aryltrifluoroborates and Aryl N-Methyliminodiacetic Acid (MIDA) Boronates