Precise structure activity relationships in asymmetric catalysis using carbohydrate scaffolds to allow ready fine tuning: dialkylzinc-aldehyde additions.
The ready construction of 24 stereochemically and functionally diverse carbohydrate ligand structures from a core D-glucosamine scaffold has allowed the evaluation of broad ranging structure activity relationships in ligand accelerated zincate additions to aldehydes, with variations in deltadeltaG+/+(R-S) of up to 5650 J mol(-1) that create opposing senses of asymmetric induction and that are consistent with models based on several ligand X-ray structures and molecular mechanics analysis. Factorial analysis of enantioselectivity using key dihedral angles and steric volume on N-2 also highlight the potential for the use of factorial design in ligand construction.
Emmerson
Daniel P G
DP
Dyson Perrins Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, UK OX1 3QY.
Villard
Renaud
R
Mugnaini
Claudia
C
Batsanov
Andrei
A
Howard
Judith A K
JA
Hems
William P
WP
Tooze
Robert P
RP
Davis
Benjamin G
BG
D000447:Aldehydes / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D013329:Structure-Activity Relationship; D015032:Zinc / Q000737:chemistry*
D000447:Aldehydes; D002241:Carbohydrates; D015032:Zinc