Synthesis of borylindenides. Complexes with iron and rhenium moieties

Borylation of lithium indenide with BBrMe2 gives the allylic 1-indenyl deri vative (1-Ind)BMe2 (1c) together with the bis-allylic connected species (1- Ind)(2)BMe (3) and with (BClPr2)-Pr-i, the allylic 1-indenyl (1-Ind)(BPr2)- Pr-i (1d); the latter, with Et3N or Py added, rearranges to the vinylic 3-i ndenyl isomer (3-Ind)(BPr)-Pr-i, (2d). The disubstituted indene C(9)H(6)Ind (SiMe3)B(O2C2Me4) (5) was prepared from Li[C9H6B(O2C2Me4)] (4b) and Me3SiCl . Both (1-Ind)BMe2 and (1-Ind)(BPr2)-Pr-i readily undergo metalation when t reated with LiTMP or LiInd to give purr 1-borylindenides Li(C9H6BMe2) (4c) and Li((C9H6BPr2)-Pr-i) (4d). A barrier to internal rotation for the BMe2 g roup of 4c of Delta G double dagger = 65.4 +/- 2.3 kJ mol(-1) was deduced f rom variable temperature H-1-NMR spectra. C-13-NMR spectra of the lithium s alts Li[C9H6B(NMe2)(2)] (4a), 4b, 4c and 4d display a deshielding of the ca rbon atoms of the Cp ring according to 4a < 4b <4c, 4d. The salts 4a and 4b were used to prepare the complexes Cp*Fe[C9H6B(NMe2)(2)] (8), Cp*Fe[C9H6B( O2C2Me4)] (9), Fe[C9H6B(O2C2Me4)](2) (10) and Re(CO)(3)[C9H6B(O2C2Me4)] (11 ), characterized by spectroscopic methods (H-1-, C-13-, B-11-NMR) and mass spectrometry. (C) 1999 Elsevier Science S.A. All rights reserved.