6533b7dafe1ef96bd126f483

RESEARCH PRODUCT

Synthesis of borylindenides. Complexes with iron and rhenium moieties

subject

description

Abstract Borylation of lithium indenide with BBrMe 2 gives the allylic 1-indenyl derivative (1-Ind)BMe 2 ( 1c ) together with the bis-allylic connected species (1-Ind) 2 BMe ( 3 ) and with BCl i Pr 2 , the allylic 1-indenyl (1-Ind)B i Pr 2 ( 1d ); the latter, with Et 3 N or Py added, rearranges to the vinylic 3-indenyl isomer (3-Ind)B i Pr 2 ( 2d ). The disubstituted indene C 9 H 6 Ind(SiMe 3 )B(O 2 C 2 Me 4 ) ( 5 ) was prepared from Li[C 9 H 6 B(O 2 C 2 Me 4 )] ( 4b ) and Me 3 SiCl. Both (1-Ind)BMe 2 and (1-Ind)B i Pr 2 readily undergo metalation when treated with LiTMP or LiInd to give pure 1-borylindenides Li(C 9 H 6 BMe 2 ) ( 4c ) and Li(C 9 H 6 B i Pr 2 ) ( 4d ). A barrier to internal rotation for the BMe 2 group of 4c of Δ G ‡ =65.4±2.3 kJ mol −1 was deduced from variable temperature 1 H-NMR spectra. 13 C-NMR spectra of the lithium salts Li[C 9 H 6 B(NMe 2 ) 2 ] ( 4a ), 4b , 4c and 4d display a deshielding of the carbon atoms of the Cp ring according to 4a 4b 4c , 4d . The salts 4a and 4b were used to prepare the complexes Cp*Fe[C 9 H 6 B(NMe 2 ) 2 ] ( 8 ), Cp*Fe[C 9 H 6 B(O 2 C 2 Me 4 )] ( 9 ), Fe[C 9 H 6 B(O 2 C 2 Me 4 )] 2 ( 10 ) and Re(CO) 3 [C 9 H 6 B(O 2 C 2 Me 4 )] ( 11 ), characterized by spectroscopic methods ( 1 H-, 13 C-, 11 B-NMR) and mass spectrometry.