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Synthesis of Peripherally Functionalised Dendritic Binaphthyl (BINAP)‐Systems and their Application as Ligands in the Copper‐Catalysed Hydrosilylation of Acetophenone
Author(s) -
Kassube Jutta K.,
Wadepohl Hubert,
Gade Lutz H.
Publication year - 2008
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.200700586
Subject(s) - chemistry , dendrimer , hydrosilylation , acetophenone , binap , ligand (biochemistry) , polymer chemistry , catalysis , stereochemistry , medicinal chemistry , enantioselective synthesis , organic chemistry , biochemistry , receptor
Two series of peripherally functionalised dendrimers were synthesised based on poly(ethyleneimine) and poly(amidoamine) (PAMAM) dendrimers by reaction of ( R )‐6‐ N ‐[(γ‐carboxyl)butanoyl]‐aminomethyl‐2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (“Glutaroyl‐Aminap”) with first to fifth generation PPI and zeroth to fourth generation PAMAM dendrimers using ethyl‐ N , N ‐dimethylcarbodiimide (EDC)/1‐hydroxybenzotriazole as coupling reagents. All dendritic ligands were characterised by NMR spectroscopy, elemental analysis and, for generations G0–G3, MALDI‐TOF mass spectrometry. The relationship between the size/generation of the dendritic ligands and their catalytic properties was established in the asymmetric hydrosilylation of acetophenone. It could be shown that ( R )‐6‐aminomethyl‐2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (“H‐Aminap”) can be attached to the dendrimers without any significant loss of catalytic selectivity compared to the monomeric ligand Benzoyl‐Aminap. The selectivities observed in these reactions were higher than those obtained using unfunctionalised BINAP as ligand.