2,2‐Difluor‐1,3‐diaza‐2‐sila‐cyclopenten – Synthese und Reaktionen

Abstract

Abstract2,2‐Difluor‐1,3‐diaza‐2‐sila‐cyclopentene – Synthesis and ReactionsN,N′‐Di‐tert‐butyl‐1,4‐diaza‐1,3‐butadiene reacts with elemental lithium under reduction to give a dilithium salt, which forms with fluorosilanes the diazasilacyclopentenes 1–4; (HCNCMe3)2SiFR, R = F (1), Me (2), Me3C (3), N(CMe3)SiMe3 (4). As by‐product in the synthesis of 1, the tert‐butyl‐amino‐methylene‐tert‐butyliminomethine substituted compound 5 was isolated, R = N(CMe3)‐CH2‐CH = NCMe3. 5 is formed in the reaction of 1 with the monolithium salt of the 1,4‐diaza‐1,3‐butadiene in an enamine‐imine‐tautomerism. 1 reacts with lithium amides to give (HCNCMe3)2SiFNHR, 6–12, R = H (6), Me (7), Me2CH (8), Me3C (9), H5C6 (10), 2,6‐Me2C6H3 (11), 2,6‐(Me2CH)2C6H3 (12). The reaction of 12 with LiNH‐2.6‐(Me2CH)2C6H3 leads to the formation of (HCNCMe3)2Si(NHR)2, (13). In the presence of n‐BuLi, 12 forms a lithium salt which looses LiF in boiling toluene. Lithiated 12 adds this LiF and generates a spirocyclic tetramer with a central eight‐membered LiF‐ring (14), [(HCNCMe3)2Si(FLiFLiNR)]4, R = 2,6‐(Me2CH)2C6H3. ClSiMe3 reacts with lithiated 12 to yield the substitution product (HCNCMe3)2SiFN(SiMe3) R, (15). The crystal structures of 1, 5, 6, 9, 11, 13, 14 are reported.