Premium
Charge‐Transfer Interactions: An Efficient Tool for Recycling Bis(oxazoline)‐Copper Complexes in Asymmetric Henry Reactions
Author(s) -
Didier Dorian,
MagnierBouvier Caroline,
Schulz Emmanuelle
Publication year - 2011
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.201000934
Subject(s) - nitromethane , nitroaldol reaction , nitroethane , chemistry , oxazoline , catalysis , covalent bond , aldol reaction , combinatorial chemistry , ligand (biochemistry) , copper , enantioselective synthesis , heterogeneous catalysis , substrate (aquarium) , organic chemistry , polymer chemistry , biochemistry , oceanography , receptor , geology
An anthracenyl‐modified chiral bis(oxazoline) copper complex has been demonstrated to efficiently promote nitroaldol reactions between structurally varying aldehydes and nitromethane or nitroethane. The catalyst was recovered through formation of a charge transfer complex between the chiral ligand and trinitrofluorenone and its subsequent precipitation with pentane. The efficiency of this procedure was proved through several consecutive catalytic cycles that allowed the sturdy formation of the expected product with a high enantioselectivity. The catalyst′s stability was also put to the test in an original multi‐substrate procedure. Following the same recovery concept, a new heterogeneous procedure was tested for which trinitrofluorenone was covalently linked to a silica support. Asymmetric heterogeneous catalysis was performed under these conditions as one of the few examples demonstrating the potential catalyst recycling in nitroaldol reactions through reversible, non‐covalent interactions.