TEMPO supported on magnetic C/Co-nanoparticles: a highly active and recyclable organocatalyst.
TEMPO was grafted on graphene-coated nanobeads with a magnetic cobalt core by using a general applicable "click"-chemistry protocol. The new heterogeneous CoNP-TEMPO emerged as a highly active catalyst for the chemoselective oxidation of primary and secondary alcohols using bleach as terminal oxidant. The outstanding stability of the C/Co nanoparticles enables the nanopowder to tolerate several TEMPO-mediated iterative oxidation reactions without any significant loss in catalyst activity. Furthermore, the excellent magnetic properties enable the rapid separation and quantitative recycling of CoNP-TEMPO out of the reaction mixture by simple magnetic decantation. The recovered nanoparticles can be subsequently reused without any further purification.
Schätz
Alexander
A
Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
Grass
Robert N
RN
Stark
Wendelin J
WJ
Reiser
Oliver
O
D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D013499:Surface Properties
D000438:Alcohols; D000447:Aldehydes; D003497:Cyclic N-Oxides; D009942:Organometallic Compounds; D003035:Cobalt; D002244:Carbon; C003959:TEMPO