Palladium nanoparticles
ligated with inexpensive triphenylphosphine
and amphiphile PS-750-M are suitable for exploring the reactivity
of carbenes in aqueous nanomicelles. Nanocatalyst is highly selective
for metal–carbene migratory insertion, and micelle of PS-750-M
shields the in situ generated carbene to prevent the dimerization.
In addition to a broad substrate scope, the nanocatalyst is thoroughly
characterized by NMR, scanning electron microscopy, high-resolution
transmission electron microscopy, X-ray photoelectron spectroscopy,
and thermogravimetric analysis. The sustainability of the reaction
system is demonstrated by the recyclability of both the catalyst and
the micellar reaction medium at variable reaction scales. NMR and
kinetics studies with the recycled catalyst revealed the retention
of catalyst integrity. Control experiments including the dynamic light
scattering study demonstrate the importance of PS-750-M.
Upon
visible-light irradiation, the heterogeneous polymer of PDI–Cu(I)–PDI
(PDI = perylene diimide) generates charge transfer states that are
subsequently quenched by molecular oxygen for their participation
in redox activity. This insoluble polymeric Cu(I) is catalytically
active for the oxidation of benzylic alcohols to corresponding aldehydes
when suspended in dynamic micelles of PS-750-M. A broad substrate
scope, excellent selectivity, and no over-oxidation reveal the catalyst
robustness. The catalytic activity, control experiments, and time-dependent
DFT calculations show the charge transfer states. The polymeric catalyst
is entirely recyclable, as evidenced by the recycle studies using
Scott’s recyclability test. The morphology, structure, copper’s
oxidation state, and the catalyst’s thermal stability are determined
by SEM, XPS, and TGA analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.