Facile Access to an NHC‐Coordinated Silicon Ring Compound with a Si=N Group and a Two‐Coordinate Silicon Atom

• Published in: Angewandte Chemie International Edition 2019-03, Vol.58 (13), p.4395-4399
• Main Authors: Keuter, Jan, Hepp, Alexander, Mück‐Lichtenfeld, Christian, Lips, Felicitas
• Format: Article
• Language: English
• Subjects: carbenes; Computer memory; Cyclic compounds; Dipping; N ligands; silaimine; Silicon; Silicon compounds; silicon ring systems; silylone; Solvents; Sulfur
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201813674

Reaction of the bicyclo[1.1.0]tetrasilatetraamide Si4{N(SiMe3)Dipp}4 1 (Dipp=2,6‐diisopropylphenyl) with 5 equiv of the N‐heterocyclic carbene NHCMe4 (1,3,4,5‐tetramethylimidazol‐2‐ylidene) affords a bifunctional carbene‐coordinated four‐membered‐ring compound with a Si=N group and a two‐coordinate silicon atom Si4{N(SiMe3)Dipp}2(NHCMe4)2(NDipp) 2. When 2 reacts with 0.25 equiv sulfur (S8), two sulfur atoms add to the divalent silicon atom in plane and perpendicular to the plane of the Si4 ring, which confirms the silylone character of the two‐coordinate silicon atom in 2. The carbene‐induced elimination of the amine NDipp(SiMe3)2 from the bicyclic silicon(I) ring compound 1 affords the bifunctional NHC‐coordinated silicon ring compound 2 with simultanous formation of a Si=N double bond and a two‐coordinate silicon atom with Si0 (“silylone”) character. The reaction of 2 with 0.25 equiv S8 confirmed the silylone character of the two‐coordinate silicon atom.