Substituent Effects of Tetracoordinate Boron in Organic Synthesis.

The present review focuses on recent examples of tetracoordinate boryl groups greatly influencing reactions in organic synthesis. Electron-rich tetracoordinate boryl groups stabilize or activate reactive intermediates such as cations, radicals and π-conjugation systems, and interaction of the intermediates with carbon-boron or heteroatom-boron bonds is the origin of such substituent effects. Unique substituent effects of tetracoordinate boryl groups often promote desired reactions and affect results of reactions such as yield and selectivity of products.