The synthesis, properties, and reactivity of Lewis acidic aminoboranes

Abstract

The evolution of frustrated Lewis pair chemistry has led to significant research into the development of new Lewis acidic boranes. Much of this has focused on modifying aryl substituents rather...

Strain-Release Promoted Thermal [2 + 2] Cycloaddition and Photochemical [2 + 2] Cycloreversion of a Tetraorganylaminoborane

“…24 Likewise, they are important in the synthesis of BN-fused aromatics and 1,2-dihydro-1,2-azaborine derivatives. 25 They found application as Lewis acids, 26 complexes with frustrated Lewis pairs, 17 and further inorganic syntheses. 27 Aminoboranes carrying hydrogen and/or halogen atoms are often dimeric in solution and in the solid state.…”

“…Likewise, they are important in the synthesis of BN-fused aromatics and 1,2-dihydro-1,2-azaborine derivatives . They found application as Lewis acids, complexes with frustrated Lewis pairs, and further inorganic syntheses …”

Exploration of bis(pentafluorophenyl)borinic acid as an electronically saturated, bench-top stable Lewis acid catalyst

“…24,25 Furthermore, our group has reported a series of aminoboranes, species of the formula R 2 N]BR 2 , that feature sterically encumbered amino groups and electron withdrawing pentauorophenyl substituents at the boron centre. 26,27 These aminoboranes have shown some stability towards atmospheric conditions and donating solvents, highlighting their potential as bench-top stable Lewis acids. 27 Despite the stability derived from the nitrogen lone pair stabilizing the empty p-orbital at boron, these species are able to maintain some Lewis acidic character through employing two strongly electron withdrawing groups, as evidenced from their high uoride ion affinities (FIA).…”

“…26,27 These aminoboranes have shown some stability towards atmospheric conditions and donating solvents, highlighting their potential as bench-top stable Lewis acids. 27 Despite the stability derived from the nitrogen lone pair stabilizing the empty p-orbital at boron, these species are able to maintain some Lewis acidic character through employing two strongly electron withdrawing groups, as evidenced from their high uoride ion affinities (FIA). Furthermore, the aminoboranes were found to be effective Lewis acid catalysts for stannane dehydrocoupling and a single example of hydrosilylation of acetophenone.…”

“…Furthermore, the aminoboranes were found to be effective Lewis acid catalysts for stannane dehydrocoupling and a single example of hydrosilylation of acetophenone. 27 Herein we expand the scope and reactivity of electronically saturated Lewis acidic boranes to borinic acids, specically bis(pentauorophenyl)borinic acid. This compound represents a potentially more sustainable Lewis acid catalyst, avoiding the need for stringently dry conditions.…”