In the micelle of
PS-750-M, the presence of 3° amides from
the surfactant proline linker mimics dimethylformamide, dimethylacetamide,
and N-methyl-2-pyrrolidone. The resultant micellar
properties enable extremely fast amide couplings mediated by 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide
(without hydroxybenzotriazole), rather than expensive and specialized
coupling agents. Conditions have been developed wherein products precipitate,
and isolation by filtration completely avoids the use of organic solvent.
This methodology is scalable and avoids product epimerization.
Although
greener and faster access to fine chemicals and APIs is
highly desirable, there are currently no synthetic methodologies which
undergo reaction completions within a few seconds to minutes in water
under benchtop laboratory conditions. Here, we report a methodology
that allows the instantaneous formation of ligated ultrasmall Pd nanoparticles
in the hydrophobic pockets of benign cellulose derivative (HPMC) for
chemical reactions to proceed very fast in water under mild reaction
conditions. Unprecedented short reaction times were exemplified for
the Buchwald–Hartwig aminations. In addition, very short reaction
times of less than a minute were also demonstrated for the amide couplings,
which is the most utilized reaction type in the pharmaceutical industry.
In the forebrain, synaptic glycine concentrations are regulated through the glycine transporter GlyT1. Because glycine is a coagonist of the N-methyl-D-aspartate (NMDA) receptor (NMDAR), which has been implicated in schizophrenia, inhibition of GlyT1 is thought to provide an option for the treatment of schizophrenia.
Scheme2.Heck-Mizorokir eaction in g-valerolactone.Scheme3.Synthesis of 1-butyl-3-methylimidazoliumchloride using scCO 2 .Scheme1.Suzuki-Miyaura coupling in 2-Me-THF.Scheme4.Improved synthetic route to sildenafilc itrate.Scheme5.Improved synthetic route to ibuprofen.Scheme6.Cu-catalyzed cyclopropanation.Scheme17. Amination in synthesis of efaproxiral.Scheme15. Peptide couplingsint he synthesis of sildenafil and sunitinib.Scheme16. Amide couplings in water.Scheme20. Couplings of unactivated (iso)quinolines in PS-750-M.Scheme21. PS-750-M as ar eplacement for toxic polar-aprotic solvent for sp 2 -sp 3 couplings.Scheme22. Recyclable palladium nanoparticles in PS-750-M for olefins ynthesis through carbene insertion.Scheme23. Drugmolecules containingC ÀNb onds.Scheme24. Recyclable bimetallic nanoparticles for sustainable Buchwald-Hartwig aminations in water.Scheme25. Ac omparison between chemistryinw ater versus chemistryino rganic solvents (Novartis Pharmaceuticals).
Commercially available hydroxypropyl
methylcellulose capsules are
employed as a fast, safe, and user-friendly chemical delivery system
containing all reagents (catalyst, ligand, and base) for three important
transition-metal-catalyzed reactions: Buchwald–Hartwig, Suzuki–Miyaura,
and metallophotoredox C–N cross-coupling reactions. This encapsulation
methodology simplifies the screening of reaction conditions and the
preparation of compound libraries using parallel synthesis in organic
solvents or aqueous media. These reagents-containing HPMC capsules
are easy to prepare, come in different sizes, and can be stored on
the bench under noninert conditions.
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