Crystalline Silylene-Stabilized Diboryne and Siladiborirene
Chuangchuang Xu, Fanshu Cao, Xingge Chen, Ming Chen, Zhenbo Mo
Abstract
The exploration of main group compounds with multiple bonds has significantly enhanced our understanding of chemical bonding and expanded transition-metal-free bond activation and catalysis. Diborynes, characterized by a boron–boron triple bond (B≡B), represent a particularly challenging area due to boron’s limited valence electrons. Here, we report the synthesis and characterization of a silylene-stabilized diboryne ( 7 ), expanding the frontier of diboryne stabilization. X-ray diffraction analysis and density functional theory calculations confirm the presence of a B≡B bond in the diboryne. Remarkably, this diboryne undergoes [1 + 2] cycloaddition reactions with dichlorosilylene and terphenyl isocyanide, producing unprecedented siladiborirene (8) and diborirenimine ( 9 ), respectively. X-ray diffraction studies show that 8 and 9 bear a three-membered boron-containing heterocycle with a B═B bond, and computational studies reveal their distinct aromatic character.