Zeolites are crystalline aluminosilicates with microporous structures. These materials have been widely used in the field of heterogeneous catalysis. [1] In most catalytic reactions involving a zeolite catalyst, the acidic sites of the zeolite play a pivotal role; hence, much attention has been paid to the nature of the acidic sites and the interactions of these sites with organic molecules.[2] The oxidation states of the framework atoms (Si, Al, and O) are thought to remain unchanged during acid-catalyzed reaction processes. However, electron loss from the zeolite framework may occur when a zeolite is subjected to a high temperature [3] or high-energy g-ray (or Xray) irradiation.[4] Electron transfer between zeolites and occluded molecules has also been proposed previously.[5] The electron-donating ability of the zeolite framework [6] and the ability of zeolites to generate organic radical cations [7] have been established by several research groups. Although it is recognized that electrons may be transferred between zeolites and occluded guest species, the nature of the electron donor/ acceptor in zeolites has not yet been elucidated clearly, and the whereabouts of the electrons/holes formed in the electron-transfer process has been under intense debate. [5,7] In particular, when zeolites act as electron donors, only occluded molecules that accept electrons from zeolites can be observed to change, whereas a difference in the zeolite framework can hardly be detected after the electron-transfer process.Herein, we demonstrate that aluminosilicate zeolites in the protonated form lose their framework electrons when alkyl bromides are introduced into the pores of the zeolites. The loss of the framework electrons results in paramagnetic centers, which function as single-electron redox sites and can be detected by electron paramagnetic resonance (EPR) spectroscopy. More importantly, this process of electron transfer accompanies the acid-catalyzed reaction between zeolites and alkyl bromides; thus, framework electron transfer of acidic zeolites should be considered to be partially responsible for the formation of some of the organic products during acid-catalyzed reactions involving zeolites.A mixture of the dehydrated zeolite HY (protonated zeolite Y with a framework Si/Al ratio of 2.46; see Figure S2 in the Supporting Information) and ethyl bromide was stirred and heated at reflux in an airtight vessel at 50 8C under argon for 24 h. We refer to this process as the "liquid-solid" (L-S) reaction. After the L-S reaction, the HY material (designated Y-R) was orange in liquid ethyl bromide and turned light pink upon the removal of the liquid alkyl bromide with a liquid-nitrogen trap (see Figure S3 in the Supporting Information). The liquid ethyl bromide remained colorless throughout the whole reaction process, both before and after trapping; in the gas phase of the product of the catalytic reaction, a small quantity of ethane was detected, besides ethene and hydrogen bromide. Figure 1 a shows the EPR spectrum of the HY zeo...

Alkene bifunctionalizations are powerful tools for the rapid construction of structurally complex and valuable scaffolds, and such reactions typically involve the use of transition‐metal catalysts or organocatalysts. Here, we report for the first time a photogenerated neutral nitrogen radical catalyzed intermolecular alkene bifunctionalization by using allyl sulfones as the source of both the carbon and the sulfone functionalities under mild conditions. The key to the success of this protocol involves the visible‐light‐mediated photocatalytic in situ generation of a nitrogen‐centered radical from the N‐(2‐acetylphenyl) benzenesulfonamide catalyst, and its activation of the allyl sulfones to generate reactive species. The preliminary control experiments supported the postulated mechanism.

A visible light photoredox-promoted and nitrogen radical catalyzed [3 + 2] cyclization of vinylcyclopropanes and Ntosyl vinylaziridines with alkenes is developed. Key to the success of this process is the use of the readily tunable hydrazone as a nitrogen radical catalyst. Preliminary mechanism studies suggest that the photogenerated nitrogen radical undergoes reversible radical addition to the vinylcyclopropanes and N-tosyl vinylaziridines to enable their ring-opening C−C and C−N bond cleavage and ensuing cyclization with alkenes.

Sulfones and alkylnitriles play a significant role in both organic and medicinal chemistry, as versatile synthetic building blocks and privileged pharmacophores in many natural products and bioactive compounds. Herein, a room‐temperature, copper‐catalyzed radical cross‐coupling of redox‐active cycloketone oxime esters and sulfinate salts is described for the first time. Key to the success of this process involves catalytic generation of a cyclic iminyl radical and ensuing ring‐opening C−C bond cleavage. The resultant cyanoalkyl radical is then engaged in cross‐coupling with nucleophilic sulfinate to form cyanoalkylated sulfones.