Silylfurans and bis(silyl)butadiynes - Synthesis, lithium derivatives, crystal structures

Furan reacts with BuLi and halosilanes to give mono- (1, 5, 7), bis- (2, 6) , tris- (3), and tetrakis(2-furanyl)silanes (4); (Fu-R; R = SiMe2Cl (1), Si isoPr(2)F (5), (SiBu2F)-Bu-t (7); Fu-R-Fu; R = SiMe2 (2), SiisoPr(2) (6); F u(3)Si(t)Bu (3), Fu(4)Si (4)), 2,5-Bis(silyl)furans (8, 9) are obtained in the reaction of dilithiated furan and fluorosilanes in a molar ratio 1:2 (R -Fu-R; R = SiisoPr(2)F (8), (SiBu2F)-Bu-t (9), 1,4-Bis(di-tert-butylfluoros ilyl)butadiyne (10) is formed from furan four equivalents of BuLi, and two equivalents of (F2SiBu2)-Bu-t. 10 reacts with KOH to give Bu-t(2)(OH)Si-C=C -C=C-(SiBu2OH)-Bu-t (11). Substitution of the fluorine atoms of 5 and 7 by a NH2 group occurs with MNH2 (M = Li, Na). 12 and 13 are obtained. The reac tion of 13 with BuLi and (Bu2SiF2)-Bu-t leads to the formation of FuSi(t)Bu (2)NHSi(t)Bu(2)F (14) and (Bu2Si)-Bu-t(NH-Si(t)Bu(2)Fu)(2) (15). The lithiu m derivative of 14 crystallizes as monomer from THF as FuSi(t)Bu(2)N(LiTHF2 )(SiBu2F)-Bu-t and as a dimer containing a four-membered ring (16) from n-h exane (FuSi(t)Bu(2)NSi(t)Bu(2)LiF)(2) (17). The crystal structures of 4, 10 , 16, 17 have been determined.