2‐Lithiumamide‐2‐fluoro‐1,3‐diaza‐2,4‐disilacyclobutanes – Syntheses, Reactions, Structures

Abstract

The cyclodisilazane Me2Si(NCMe3)2SiF2 (1) reacts with lithium salts of ammonia (2), hydrazine (3) and amines (4–10) to give the stable compounds Me2Si(NCMe3)2SiFNHR (R = H (2), NH2 (3) CMe3 (4), C10H15 (5), 3,5‐C6H3Me2 (6), 2,4,6‐C6H2Me3 (7), 2,6‐C6H3(CHMe2)2 (8), C6F5 (9), Si(CMe3)2Ph (10)). Compounds 2–10 show no condensation reactions with formation of NH3, N2H4, or amines. Dilithiummethylenediamide reacts with 1 to give the ethylenediamine coupled ring system 11 or spirocyclic compound 12. Compounds 2, 3, 4 form the spirocyclic systems 13–15 in reactions with n‐C4H9Li. A partly hydrolysed lithium salt (16) was isolated as tetramer containing a central Li6O octahedron. The lithium salts of 5 (17), 9 (19) and 10 (20) were isolated as monomers (17, 19) or dimer, respectively, via an (LiN)‐four‐membered ring (20). Crystal structures of 3, 9, 13–17, 19 and 20 are reported.