<i>N</i>,<i>N</i>‑Dimethylformamide (DMF) as a Source of Oxygen To Access α‑Hydroxy Arones via the α‑Hydroxylation of Arones

An unprecedented α-hydroxylation strategy was developed for the synthesis of α-hydroxy arones using <i>N</i>,<i>N</i>-dimethylformamide (DMF) as an oxygen source. Control experiments demonstrated that the oxygen atom of the hydroxy group in the α-hydroxy arones produced in this reaction was derived from DMF. This new reaction therefore not only provides an alternative strategy for the α-hydroxylation of arones but also highlights the possibility of using the inexpensive common solvent DMF as a source of oxygen in organic synthesis

Preparation of 1,2-Oxazetidines from Styrenes and Arylamines via a Peroxide-Mediated [2 + 1 + 1] Cycloaddition Reaction

The first regioselective synthesis of polysubstituted 1,2-oxazetidines, based on the [2 + 1 + 1] radical tandem cycloaddition of styrenes, arylamines, and <i>tert</i>-butyl hydroperoxide (TBHP), is described. This simple and direct method allows the synthesis of 1,2-oxazetidines with a broad substrate scope from easily accessible materials. TBHP was employed in this conversion not only as the oxidant but also as the source of “O” for the carbonyl group in the products

Nitrilase-Activatable Noncanonical Amino Acid Precursors for Cell-Selective Metabolic Labeling of Proteomes

Cell-selective protein metabolic labeling is of great interest for studying cell–cell communications and tissue homeostasis. We herein describe a nitrilase-activatable noncanonical amino acid tagging (NANCAT) strategy that exploits an exogenous nitrilase to enzymatically convert the nitrile-substituted precursors to their corresponding noncanonical amino acids (ncAAs), l-azidohomoalanine (Aha) or homopropargylglycine (Hpg), in living cells. Only cells expressing the nitrilase can generate Aha or Hpg <i>in cellulo</i> and metabolically incorporate them into the nascent proteins. Subsequent click-labeling of the azide- or alkyne-incorporated proteins with fluorescent probes or with affinity tags enables visualization and proteomic profiling of nascent proteomes, respectively. We have demonstrated that NANCAT can serve as a versatile strategy for cell-selective labeling of proteomes in both bacterial and mammalian cells

Organosilane with Gemini-Type Structure as the Mesoporogen for the Synthesis of the Hierarchical Porous ZSM‑5 Zeolite

A new kind of organosilane (1,6-bis­(diethyl­(3-trimethoxysilylpropyl)­ammonium) hexane bromide) with a gemini-type structure was prepared and used as a mesoporogen for the synthesis of hierarchical porous ZSM-5 zeolite. There are two quaternary ammonium centers along with double-hydrolyzable −RSi­(OMe)₃ fragments in the organosilane, which results in a strong interaction between this mesoporogen and silica–alumina gel. The organosilane can be easily incorporated into the ZSM-5 zeolite structure during the crystallization process, and it was finally removed by calcination, leading to secondary pores in ZSM-5. The synthesized ZSM-5 has been systematically studied by XRD, nitrogen adsorption, SEM, TEM, TG, and solid-state one-dimensional (1D) and two-dimensional (2D) NMR, which reveal information on its detailed structure. It has a hierarchical porosity system, which combines the intrinsic micropores coming from the crystalline structure and irregular mesopores created by the organosilane template. Moreover, the mesoposity including pore size and volume within ZSM-5 can be systematically tuned by changing the organosilane/TEOS ratio, which confirms that this organosilane has high flexibility of use as a template for the synthesis of hierarchical porous zeolite