Trifunctional organometallic frameworks and cages based on all-cis-1,3,5-triethynyl-1,3,5-trisilacyclohexanes

Abstract

All-cis-1,3,5-triethynyl-1,3,5-triorganyl-1,3,5-trisilacyclohexanes offer flexible scaffolds with three concordantly oriented ethynyl groups that can be lithiated and transformed into a range of other cage-like compounds, like the trimercury cage compounds [CH2Si(R)C2HgC2(R)SiCH2]3 shown in the picture.

HMPA-Free Synthesis of TMS-Substituted Alkynes

“…Nevertheless, the solid-state arrangement of 24 could be determined unambiguously showing a tetrameric cubic structure with each terminal acetylide carbon linked to three lithium atoms, the fourth coordination site of each lithium atom being completed by the DMPU coordination through oxygen. This solid-state cubic aggregation of 24 is analogous to previously characterized members of the lithium acetylide family [( t Bu-CC–Li) 4 (THF) 4 ], [( t Bu-CC–Li) 4 (IMe) 4 ], [(Ph–CC–Li) 4 (tmpda) 4 ], and [(Ph–CC–Li) 4 (tmhda) 4/2 ] The X-ray diffraction structure of 24 represents the first structural evidence of a lithium trimethylsilylacetylide derivative . As the reactivity of organolithium reagents is strongly dependent on their aggregation state, we wonder if the solid-state tetrameric structure of 24 was maintained in THF solutions .…”