constitutes an untapped resource. [5][6][7] In addition, tailoring molecules by adding redox-active functional groups can modulate both redox potentials and electrontransfer rates. [8,9] Thus, the vast array of organic molecules can construct a new class of electrodes, [10,11] if the main problems, such as excessive solubility, poor electronic conductivity, and vulnerability to chemical side reactions, can be solved. [5][6][7][8][9] A promising answer to these problems is the integration of small molecules into a crystalline network scaffold. [12,13] Covalent organic frameworks (COF) are well suited to form stable molecular crystals [14,15] ; Integration of organic building blocks via strong covalent bonds creates 2D structures, which are layered upon one another and held in place by π-π interactions. The resulting 3D structures inhibit the dissolution of the organic layers. Moreover, periodic mesopores are formed across the entire structure, providing effective ion-transport channels. [16][17][18] Typically, COF electrodes comprise redox functionality and linkage molecules, where the latter is responsible for the shape, mesopore size, π-conjugation, and stability of the COF. [13,19] Heteroatom-containing molecular linkers have been widely utilized to improve the wettability of COFs in electrolyte solutions. [20][21][22][23] β-Ketoenamine-linked COFs have been extensively used for capacitor and battery electrodes, and solid-state electrolytes. [24][25][26] However, a β-ketoenamine unit typically forms a nonconjugated in-plane structure of the COF, [26,27] the effect of which during electrochemical conditions has not yet been studied in depth. Imine linkage comprises partial π-conjugation over the 2D COF layer. [28,29] However, chemical instability of imine has been widely known, for example, hydrolysis in an acidic solution. [30] Therefore, the role of imine linkage remains to be explored in the nonaqueous solution-based electrochemical cells. Thiazole linkage has been recently developed to satisfy both chemical stability and the π-conjugated system. [31][32][33] Sulfur-containing thiazole, thiophene, and tetrathiafulvalene are a new class of moieties embedded into COFs and show excellent charge mobility and conductivity. [34][35][36][37] Thus, they have extended the applications of COFs to molecular electronics, and energy conversion and storage electrodes. [38][39][40][41][42][43] However, there is still a lack of study that proves true chemical and electrochemical stability of thiazole-linked COF under the battery operating conditions.Covalent organic frameworks (COFs) have been considered a potentially versatile electrode structure if they are made highly conductive and flexible to stabilize the redox functionality. Although conceptually plausible, COF-based electrodes have rarely satisfied high capacity, cyclability, and rate capability thus far. Incorporating thiazole moieties into the organic scaffold, it is able to fabricate π-conjugated and crystalline organic electrodes and demonstrate the fast two-elec...

We herein disclose the Cp*Co­(III)­(LX)-catalyzed amidative alkyl migration using 2,6-disubstituted phenyl azidoformates. Upon the cobalt–nitrenoid insertion toward the substituted ortho carbon, an arenium cationic species bearing a quaternary carbon is generated, and a subsequent alkyl migration process is suggested to occur through an unforeseen alkyl-walking mechanism. A quinolinol ligand of the cobalt catalyst system is proposed to facilitate the final product-releasing rearomatization process by serving as an internal base. This new mechanistic mode enabled both [1,2]- and [1,4]-alkyl rearrangements to allow the structural variation of N-heterocyclic compounds.

A highly efficient one-pot synthesis of 3-azidopiperidines has been achieved by an intramolecular cyclization of unsaturated amines that allows for the nucleophilic installation of an azide moiety. This method unlocks the versatile employment of the azide functionality in the preparation and biological studies of piperidine-containing structures. This strategy has been expanded for the direct incorporation of a variety of nitrogen nucleophiles, and thus it provides a rapid and modular synthesis of 3-amino and 3-amidopiperidines of important pharmaceutical and biological relevance. Particularly noteworthy is that the regioselectivity of this transformation enables the formation of the anti-Markovnikov-type adduct, complementing Markovnikov-based olefin amino functionalization methods.

We disclose herein a Cp*Co(III)(LX)-catalyzed dearomative Diels−Alder dimerization of 2,6-disubstituted phenyl azidoformates. Upon the postulated cobalt-nitrenoid insertion into the neighboring ortho-carbon, the key intermediate of ortho-quinamine was generated for the subsequent dimeric cycloaddition process. A series of experimental and computational studies suggested that the quinolinol ligand of the cobalt catalyst plays a crucial role in the alcoholic solvent incorporation into the o-quinamine moiety, thereby enabling the Diels− Alder dimerization to furnish the bridged tricyclic bisamidation products.