1015074-86-8Relevant articles and documents
DIPHOSPHINES AND METAL COMPLEXES
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Page/Page column 29-30, (2008/06/13)
Compounds of the formulae (I) and (II), or a mixture of these enantiomers, where R'1 is C1-C4-alkyl and n is 0, 1 or 2; R1 is C1-C8-alkyl, C2-C8-alken-1-yl, -CH2-OR or - CH2-NR5R6; the two radicals R2 are identical or different and are each hydrogen or a monovalent radical of an electrophilic organic compound, or one R2 has this meaning and the other R2 is hydrogen; sec-phos is a secondary phosphino group; R is C1-C8- alkyl and R5 and R6 are each C1-C6-alkyl or R5 and R6 together form tetramethylene, pentamethylene or 3-oxa-1,5-pentylene, are ligands for metal complexes which can be used as valuable homogeneous catalysts for asymmetric syntheses. The compounds are obtained by a novel process in which 3,3'-metallated 1,1'-di-R1-2,2'- dibromoferrocenes are firstly reacted with sec-phos halide, the bromine atoms are then replaced by lithium and the substituent R2 is subsequently introduced by reaction with an electrophilic organic compound or with water.