Biferrocene diphosphine

A series of frani -chelating chiral biferrocene diphosphine ligands enable a rhodium(I)-catalysed aldol reaction of 2-cyanopropionates to proceed in up to 93%... 

Excellent ee-values (up to 94%) have been obtained for the hydrogenation of various 2-substituted N-acetyl indoles with an in-situ prepared rhodium catalyst modified with the trans-chelating diphosphine (S,S)-(R,R)-2,2"-bis[l-(diphenyl-phosphino)ethyl]-1,1"-biferrocene (Scheme 16.23) [88]. A strong base was required as co-reagent to observe both high conversion (TOFs of 50-100) and en-... 

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