P‑Directed Borylation of Phenols

Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf₂ to give heterocyclic intermediates that can be reductively quenched to afford <b>6</b> or treated with KHF₂ to give the phenolic potassium aryl trifluoroborate salts <b>10</b>. The latter salts are useful for Pd-catalyzed coupling with aryl iodides under Molander conditions, provided that precautions are taken to remove the KNTf₂ byproduct from the preceding KHF₂ step

P‑Directed Borylation of Phenols

Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf₂ to give heterocyclic intermediates that can be reductively quenched to afford <b>6</b> or treated with KHF₂ to give the phenolic potassium aryl trifluoroborate salts <b>10</b>. The latter salts are useful for Pd-catalyzed coupling with aryl iodides under Molander conditions, provided that precautions are taken to remove the KNTf₂ byproduct from the preceding KHF₂ step

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Kinetics of the Cationization of Cotton

Cationic cotton has a greater affinity for reactive dyes than untreated cotton, providing economic and environmental advantages for the textile industry. The reaction by which a cationic group is appended to cotton suffers from a competing hydrolysis in the aqueous medium; the inefficiency of the cationization under desired processing conditions currently limits widespread application. A study of the kinetics of the competing processes provided insight into the mechanism of hydrolysis and of the reaction with cotton, enabled by high-throughput parallel reactors. The reaction kinetics and the dependences on temperature and catalytic NaOH are well-defined under a range of industrially useful conditions. The temperature profiles of the competing reactions are similar, and both have the same first-order dependences on [NaOH]. Changing the amount of excess catalytic base and the temperature are therefore not expected to have a significant effect on reaction efficiency but can be used to control the time required for a reaction to go to completion. A rationale for the enhancement of reaction efficiency by organic cosolvents is also described

Resolving and Controlling Photoinduced Ultrafast Solvation in the Solid State

Solid-state solvation (SSS) is a solid-state analogue of solvent–solute interactions in the liquid state. Although it could enable exceptionally fine control over the energetic properties of solid-state devices, its molecular mechanisms have remained largely unexplored. We use ultrafast transient absorption and optical Kerr effect spectroscopies to independently track and correlate both the excited-state dynamics of an organic emitter and the polarization anisotropy relaxation of a small polar dopant embedded in an amorphous polystyrene matrix. The results demonstrate that the dopants are able to rotationally reorient on ultrafast time scales following light-induced changes in the electronic configuration of the emitter, minimizing the system energy. The solid-state dopant–emitter dynamics are intrinsically analogous to liquid-state solvent–solute interactions. In addition, tuning the dopant/polymer pore ratio offers control over solvation dynamics by exploiting molecular-scale confinement of the dopants by the polymer matrix. Our findings will enable refined strategies for tuning optoelectronic material properties using SSS and offer new strategies to investigate mobility and disorder in heterogeneous solid and glassy materials