“…In 2008, N∧C-chelate tetra-coordinated organoboranes, such as B(ppy)Mes 2 (ppy = 2-phenyl pyridine, Mes = mesityl), were found to display unique thermally reversible photoisomerization. From then on, consistent research effort from Wang, Wagner, Braunschweig, Jäkle, and Yamaguchi et al ,,− ,− has been given to not only expand the scope of photoactive organoboranes but also comprehensively understand their rare photoactive properties. For instance, diaryl chelate units were believed to be necessary for photochemical reactivity for a long time.…”