Non-planar Boron Lewis Acids Taking the Next Step: Development of Tunable Lewis Acids, Lewis Superacids and Bifunctional Catalysts

Abstract

Although boron Lewis acids commonly adopt a trigonal planar geometry, a number of compounds in which the trivalent boron atom is located in a pyramidal environment have been described. This review will highlight the recent developments of the chemistry and applications of non-planar boron Lewis acids, including a series of non-planar triarylboranes derived from the triptycene core. A thorough analysis of the properties and of the influence of the pyramidalization of boron Lewis acids on their stereoelectronic properties and reactivities is presented based on recent theoretical and experimental studies.1 Non-planar Trialkylboranes2 Non-planar Alkyl and Aryl-Boronates3 Non-planar Triarylboranes and Alkenylboranes3.1 Previous Investigations on Bora Barrelenes and Triptycenes3.2 Recent Work on Boratriptycenes from Our Research Group4 Applications of Non-planar Boranes4.1 Non-planar Alkyl Boranes and Boronates4.2 Non-planar Triarylboranes (Boratriptycenes)5 Other Non-planar Group 13 Lewis Acids6 Further Work and Perspectives