"Nok": a phytosterol-based amphiphile enabling transition-metal-catalyzed couplings in water at room temperature.
The third-generation designer amphiphile/surfactant, "Nok" (i.e., SPGS-550-M; β-sitosterol methoxypolyethyleneglycol succinate), soon to be commercially available from Aldrich, can be prepared in two steps using an abundant plant feedstock and β-sitosterol, together with succinic anhydride and PEG-550-M. Upon dissolution in water, it forms nanomicelles that serve as nanoreactors, which can be characterized by both cryo-TEM and dynamic light scattering analyses. Several transition-metal-catalyzed reactions have been run under micellar conditions to evaluate this surfactant relative to results obtained in nanoparticles composed of TPGS-750-M (i.e., a second-generation surfactant). It is shown that Nok usually affords yields that are, in general, as good or better than those typically obtained with TPGS-750-M, and yet is far less costly.
Department of Chemistry and Biochemistry, University of California , Santa Barbara, California 93106, United States.
Piyatida
P
Klumphu
Bruce H
BH
Lipshutz
D002384:Catalysis; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry*; D010840:Phytosterols / Q000737:chemistry*; D011092:Polyethylene Glycols; D012855:Sitosterols / Q000138:chemical synthesis* / Q000737:chemistry*; D013386:Succinates / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D028561:Transition Elements / Q000737:chemistry*; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D010840:Phytosterols; D012855:Sitosterols; D013386:Succinates; D013501:Surface-Active Agents; D028561:Transition Elements; D014867:Water; D014810:Vitamin E; D011092:Polyethylene Glycols; C014225:tocophersolan