Complexes bearing an enantiopure N,N,O scorpionate ligand derived from (-)-menthone

摘要

Starting from (-)-menthone an enantiopure chiral tripod ligand is obtained via C-2 symmetric bis(menthylpyrazol-1-yl)methane bpm(4menth) (2c) by introducing a carboxylate donor at the bridging carbon atom. A prochiral centre but no additional stereo centre is formed at this carbon atom resulting in a homochiral tripod ligand bpa(4menth)H (3). As first examples, the complexes [Ru(bpa(4menth))Cl(PPh3)(2)](4), [Mn(bpa(4menth))(CO)(3)](5) and [Re(bpa(4menth))(CO)(3)] (6) bearing this enantiopure scorpionate ligand were synthesized. Single-crystal X-ray structure analyses of bpm(4menth) (2c), bpa(4menth)H (3) and [Re(bpa(4menth) (CO)(3)] (6) are reported, too. (C) 2003 Elsevier Ltd. All rights reserved.