The introduction of electron‐donating, bridging guanidinate substituents in diborane(4) compounds allows the synthesis of a variety of new cationic diborane(4) compounds. In this work, strategies for the directed synthesis of cationic di‐ and tetraboron compounds are presented, leading to the synthesis and complete characterization of several new compounds with distinct structural motifs, all exhibiting BII atoms directly bound to each other. Hence, we report on tetracationic donor‐acceptor cyclophanes with diboron donor linkers and organic π‐acceptor units, on paddlewheel‐type cationic diboranes, and on unsymmetrically‐substituted monocationic diboranes.

In this work we report the first cycloaddition reactions between a diazido diborane(4) and terminal alkynes, providing unique access to bis-1,2,3-triazoles connected by a BÀ B bridge. The catalyst-free reactions are highly selective, yielding exclusively the thermodynamically disfavored bis-1,4triazoles. The reactions are enabled by the high thermal stability of the diazido-diborane [B(hpp)(N 3 )] 2 (hpp = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-α]pyrimidinate). Due to the tetra-coordinate boron atoms in this reagent, the reactions are tolerant with respect to the introduction of Lewis-basic groups at the alkyne. The scope and limitations of the new reactions are discussed.