Micellar catalysis-enabled sustainable ppm Au-catalyzed reactions in water at room temperature

Abstract

Several ppm level gold-catalyzed reactions enabled by the ligand HandaPhos can be performed at room temperature in aqueous nanoreactors composed of the surfactant Nok.

Bridging the gap between transition metal- and bio-catalysis via aqueous micellar catalysis

“…Notably, even 2 mol% of Pd (i.e., 20,000 ppm) is well tolerated by the enzyme. Switching to ppm-level gold catalysis, generation of ketones in situ via hydration of alkynes 46 followed by their reduction to the corresponding nonracemic alcohols led to excellent results as well (Fig. 7a).…”

The Hydrophobic Effect Applied to Organic Synthesis: Recent Synthetic Chemistry “in Water”

“…[67] These and several other fascinating and intriguing discoveries, as detailsa ssociated with the various topics in this review,a re presented herein. There are also many "firsts" in micellar catalysis appliedt oo rganic synthesis, such as:1 )new ligands designed for applications based on micellar catalysis in water; [17,19,23,38] 2) ppm level metal-catalyzed processes; [27,39,50,54,56] 3) new heterogeneous nanoparticles that catalyze av ariety of important, commonly utilized reactions; [27,39,49,50] 4) new hybrid micellar derivatives that incorporate reagents within their structure; [25,49,67,69] 5) industrially important developments on the use of micelles influenced by the presenceo fc o-solvents; [75][76][77][78] and 6) examples of one-pot tandem processes enabled by micellar conditions. [27,81,82,85,88,89] These and several relatede xamples from just the past few years further documentt he potentialo ft his blossoming technology,i llustrating new synthetic chemistry that is sustainable, environmentally responsible, and acknowledges that chemistry as practiced today must be changedt ob ei ns tep with the laws of Nature.…”

“…By increasing the binding constant of metal-ligand complexes to the inner hydrophobic core of nanomicelles, the time spent within the reaction center( as opposed to exchanging between micelles)c an be increased as well, thus reducing the amount of metal neededf or catalysis.L ipophilic HandaPhos, [19] initially designed for Pd-catalyzed Suzuki-Miyaura cross-coupling reactions (vide supra), provedt ob ee fficient as its 1:1c omplex with gold in variousg old-catalyzed reactions, these taking place in micellesd erived from aqueous SPGS-550-M (Nok) (Scheme 30). [56] The loading (typically 1-5 mol %f or traditional couplings in organic solvents) [57] could be dramatically reduced, while chlorinated solvents were completely eliminated. Dual catalysis using ac ombinationo f1 000 ppm (tetrahydrothiophene)AuCl + HandaPhos with 2000 ppm of silver salt AgSbF 6 in the presence of two equivalents of TFAl ed to cycli-Scheme28.…”

Micelle‐Enabled One‐Pot Guanidine Synthesis in Water Directly from Isothiocyanate using Hypervalent Iodine(III) Reagents under Mild Conditions

“…[1][2][3] Since then many elegant reactions have been reported. [4][5][6][7][8][9][10][11][12] Although on-water reactions offer much benefits, wide-spread adoption has been limited by inability of on-water reaction to be adapted to all traditional chemical transformation reactions due to heterogeneous behaviour.I nr ecent years, new developments in surfactant technology created by Lipshutz [13][14][15][16][17][18] and others [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] have significantly made an improvement for aqueous reactions allowing reaction to occur "in-water" via the formation of micelles,t hereby providingh igh reproducibility and reactivity.…”