Metal complexes of biologically important ligands, XCVII. Synthesis and characterisation of cyclometallated compounds of Schiff bases from α-amino acid esters with manganese (I) and rhenium (I) carbonyls
N-Diphenylmethylen Schiffbasesfromα-aminoacidesters react with MnMe(CO)5 and ReMe(CO)5 in refluxing octane to give the orthometallated complexes (CO)4M[C6H4(C6H5)CNCHR1CO2R2}-C,N] (MMn, Re). Reactions of the orthometallated rhenium complexes with HBF4 afford ionic N,O-chelate complexes under cleavage of the Re–C bond. The structures of the valine derivatives of the orthomanganated and -rhenated
ñ从-Diphenylmethylen Schiff碱α -氨基酸的酯与MnMe(CO)反应5和雷默(CO)5在回流辛烷,得到orthometallated络合物(CO)4 M [C 6 H ^ 4(C 6 H ^ 5)C NCHR 1 CO 2 - [R 2 } -C,N](MMn中,Re)。在Re-C键断裂的情况下,原金属化的–配合物与HBF 4的反应生成离子型N,O-螯合物。通过X-射线衍射测定正锰和正hen的配合物的缬氨酸衍生物的结构。
Investigation into the enantioselective protonation of enolate Schiff bases with (R)-pantolactone
作者:Monique Calmès、Christèle Glot、Jean Martinez
DOI:10.1016/s0957-4166(00)00500-0
日期:2001.2
The effect of several factors on the enantioselective protonation of the enolates of a-amino acid derivatives with (R)-pantolactone were studied. The highest stereoselectivity (74-76% e.e.) was generally observed by associating lithium chloride with LHMDS and by using the optimum temperature for the formation of the enolate. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.