C–H Hydroxylation of Phosphonates with Oxygen in [bmIm]OH To Produce Quaternary α‑Hydroxy Phosphonates

A highly efficient and mild [bmIm]­OH-catalyzed α-hydroxylation of phosphonates using O₂ as the oxygen source is described. The employment of ionic liquid under mild reaction conditions makes this transformation green and practical. Especially, this reaction provided a novel and convenient methodology for the construction of quaternary α-hydroxy phosphonates

Experimental and theoretical study of I₂-catalyzed dialkenyl oxindoles synthesis from isatins and α-cyano ketene ethylene dithioacetal

<p>An I₂-catalyzed synthesis of dialkenyl oxindoles from isatins and α-cyano ketene ethylene dithioacetal is described. Both electron-withdrawing groups (EWGs) and alkylthio groups exert effects on the reactivities of ketene dithioacetals. Density functional theory (DFT) calculations suggested that the highest negative charge density on the α-carbon of α-cyano ketene ethylene dithioacetal and the largest positive charge on C(3) of the related key intermediate are both responsible for the superior activity of α-cyano ketene ethylene dithioacetal. The cationic intermediate derived from 2-(1,3-dithian-2-ylidene)acetonitrile is the most stable but the least positive, thus the corresponding alkenylhydroxyoxindole is the thermally stable and separable product. Other ketene dithioacetals are less nucleophilic, and their corresponding cationic intermediates are probably not positive enough to enable further transformation.</p

Laterally Expanded Rylene Diimides with Uniform Branched Side Chains for Solution-Processed Air Stable n‑Channel Thin Film Transistors

Molecular packing motifs in solid states is the dominant factor affecting the n-channel organic field-effect transistors (OFETs). However, few systematic researches were performed in the different extensions of π-conjugated molecules with the uniform substitution effecting the molecular packing motifs. In this manuscript, OFET devices based on three latterally expanded rylene diimides end-functionalized with uniform 3-hexylundecyl substitution on the imide positions were systematically studied on the relationship of molecular stacking, film microstructure, and charge transport. As the π-conjugated systems expanded from doubly linked perylene diimide dimer (d-4CldiPDI, <b>1</b>), triply linked perylene diimide dimer (t-4CldiPDI, <b>2</b>), to hybrid array (NDI-PDI-NDI, <b>3</b>), their corresponding molecular packing motifs exhibited a divide: the optimized molecular configuration became more planar and <i>d</i> (001) spacing distances became larger, which resulted in a larger π–π overlapping. Thus, an enhanced electron mobility was obtained. A typical n-channel field-effect characteristic was observed in thin film devices based on these molecules under ambient conditions. Especially, the hybrid system (<b>3</b>) with more planar and π-expanded aromatic backbone exhibited superior electron mobility approaching 0.44 cm² V^–1 s^–1 and on/off ratio of 10⁶ after optimal annealing in this study

Catalyst-free synthesis of 3-(1-arylsulfonylalkyl)indoles via three-component reaction of indoles, carbonyls, and arenesulfinic acids

<p>A catalyst-free three-component reaction of indoles, carbonyls, and arenesulfinic acids performed at room temperature provides direct access to biologically important 3-(1-arylsulfonylalkyl)indoles. This process features mild conditions, low cost, broad substrate scope, and high yields, and mechanistically bis(indolyl)methanes were identified as the key intermediates.</p