In one embodiment, the present application discloses mixtures comprising (a) water in an amount of at least 1% wt/wt of the mixture; (b) a transition metal catalyst; and (c) one or more solubilizing agents; and methods for using such mixtures for performing transition metal mediated bond formation reactions.
Manipulating Micellar Environments for Enhancing Transition Metal-Catalyzed Cross-Couplings in Water at Room Temperature
作者:Bruce H. Lipshutz、Subir Ghorai、Wendy Wen Yi Leong、Benjamin R. Taft、Daniel V. Krogstad
DOI:10.1021/jo200746y
日期:2011.6.17
The remarkable effects of added salts on the properties of aqueous micelles derived from the amphiphile PTS are described. Most notably, Heck reactions run in the presence of NaCl lead to couplings on aryl bromides in water at roomtemperature. Olefin cross- and ring-closingmetathesis reactions run in the presence of small amounts of pH-lowering KHSO4 are also accelerated, another phenomenon that
Rate Enhanced Olefin Cross-Metathesis Reactions: The Copper Iodide Effect
作者:Karl Voigtritter、Subir Ghorai、Bruce H. Lipshutz
DOI:10.1021/jo200360s
日期:2011.6.3
Copper iodide has been shown to be an effective cocatalyst for the olefin cross-metathesis reaction. In particular, it has both a catalyst stabilizing effect due to iodide ion, as well as copper(I)-based phosphine-scavenging properties that apply to use of the Grubbs-2 catalyst. A variety of Michael acceptors and olefinic partners can be cross-coupled under mild conditions in refluxing diethyl ether
In one embodiment, the present application discloses mixtures comprising (a) water in an amount of at least 1% wt/wt of the mixture; (b) a transition metal catalyst; and (c) one or more solubilizing agents; and methods for using such mixtures for performing transition metal mediated bond formation reactions.
“Nok”: A Phytosterol-Based Amphiphile Enabling Transition-Metal-Catalyzed Couplings in Water at Room Temperature
作者:Piyatida Klumphu、Bruce H. Lipshutz
DOI:10.1021/jo401744b
日期:2014.2.7
The third-generation designer amphiphile/surfactant, "Nok" (i.e., SPGS-550-M; beta-sitosterol methoxypolyethyleneglycol succinate), soon to be commercially available from Aldrich, can be prepared in two steps using an abundant plant feedstock and beta-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.