report an efficient one‐step annulative π‐extension reaction of alkynes that provides access to diarylphenanthrenes and related nanographene precursors. In the presence of a cationic palladium/o‐chloranil catalyst system and dibenzosiloles or dibenzogermoles as π‐extending agents, a variety of diarylacetylenes are transformed successfully into 9,10‐diarylphenanthrenes in a single step with good functional‐group
Rhodium-Catalyzed Silylative and Germylative Cyclization with Dehydrogenation Leading to 9-Sila- and 9-Germafluorenes: A Combined Experimental and Computational Mechanistic Study
rate constant of dehydrogenative germylation was greater than that of dehydrogenative silylation. Competitive reactions in the presence of 3,3‐dimethyl‐1‐butene indicated that the ratio of dehydrogenative metalation and hydrometalation was affected by reaction temperature when a hydrosilane or hydrogermane precursor was used. Further mechanistic insights of oxidant‐free dehydrogenative silylation, including
The synthesis and characterization of a spirosilabifluorene cyclic trimer have been successfully demonstrated. The HOMO and LUMO energy levels were decreased through the C/Si substitution in the spiro-atom of spirobifluorene in the cyclic trimer. Furthermore, the chiroptical properties were investigated from both experimental and theoretical points of view with careful discussion.
螺硅二芴环状三聚体的合成和表征已得到成功证明。 HOMO 和 LUMO 能级通过环状三聚体中螺二芴的螺原子中的 C/Si 取代而降低。此外,从实验和理论的角度研究了手性光学性质,并进行了仔细的讨论。
Rhodium-Catalyzed Synthesis of Silafluorene Derivatives via Cleavage of Silicon−Hydrogen and Carbon−Hydrogen Bonds
The rhodium-catalyzed synthesis of silafluorenes from biphenylhydrosilanes is described. This highly efficient reaction proceeds via both Si-H and C-H bond activation, producing only H-2 as a side product. Using this method, a ladder-type bis-silicon-bridged p-terphenyl could also be synthesized.