Bio-catalytic reactions involving ene-reductases (EREDs) in tandem with chemo-catalysis in water can be greatly enhanced by the presence ofnanomicelles derived from the surfactant TPGS-750-M. Transformations are provided that illustrate the...
The concept of complementary semiconducting
polymer blends (c-SPBs) has been recently proposed
to achieve enhanced solution
processability and/or melt-processing capability for organic electronics.
In the previous study, we demonstrated the impact of conjugation-break
spacers of matrix polymers. In the current work, we explore the influence
of the side chains of the matrix polymer on the physical properties
of the pure polymers and their corresponding c-SPBs,
including electrical properties and phase transition behaviors. Six
diketopyrrolopyrrole (DPP)-based polymers with pentamethylene
conjugation-break spacers (CBSs) and various side chains, including
branched-alkyl, triethylene glycol (TEG), and siloxane-terminated
side chains, were synthesized and characterized. The UV–vis
spectra show that the side chains have a noticeable impact on the
intermolecular interactions in the solid states. In addition, side
chains also have a significant influence on the thermal behaviors
of the polymers. Polymers with asymmetric side chains attached to
the same DPP unit exhibit lower melting points compared to the congeners
with symmetric side chains. The polymer with both branched-alkyl and
TEG side chain exhibits the lowest melting point of 104 °C. As
for charge transport properties, polymers with branched-alkyl and/or
siloxane-terminated side chains give hole mobilities on the same order
of magnitude, whereas the polymers with TEG side chains exhibits much
lower mobilities. When c-SPBs with a fully conjugated
polymer with branched-alkyl side chains are concerned, the c-SPBs of all polymers, except for the polymer with only
TEG side chains (TEG-DPP-C5), show hole mobilities 2 orders of magnitude
higher than the corresponding pure matrix polymers. In contrast, TEG-DPP-C5
merely presents an improvement of 20 times, which resulted from the
incompatibility of TEG side chains from the matrix polymer and the
alkyl side chains from the tie chain polymer. These results provide
new insights into structural design for semiconducting materials with
both high performance and better processability.
Esterification in an aqueous micellar medium is catalyzed by a commercially available lipase in the absence of any co-factors. The presence of only 2 wt % designer surfactant, TPGS-750-M, assists...
New technology is described that enables late stage ppm Pd‐catalyzed cyanations of highly complex molecules, as well as a wide variety of aryl and heteroaryl halides possessing sensitive functional groups. These reactions are efficient in water containing nanomicelles, formed from a commercially available and inexpensive surfactant. The implications for advancing drug synthesis and discovery are apparent.
Mild mono‐ and di‐hydrodehalogenative reductions of gem‐dibromocyclopropanes are described, providing an easy and green approach towards the synthesis of cyclopropanes. The methodology utilizes 0.5–5 mol % TMPhen‐nickel as the catalyst, which, when activated with a hydride source such as sodium borohydride, cleanly and selectively dehalogenates dibromocyclopropanes. Double reduction proceeds in a single operation at temperatures between 20–45 °C and at atmospheric pressure in an aqueous designer surfactant medium. At lower loading and either in the absence of ligand or in the presence of 2,2′‐bipyridine, this new technology can also be used to gain access to not only monobrominated cyclopropanes, interesting building blocks for further use in synthesis, but also mono‐ or di‐deuterated analogues. Taken together, this base‐metal‐catalyzed process provides access to cyclopropyl‐containing products and is achieved under environmentally responsible conditions.
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