Depending on the reactant property and reaction mechanism, one major regioisomer can be favored in areaction that involves multiple active sites.H erein, an orthogonal regulation of nucleophilic and electrophilic sites in the regiodivergent hydroamination of isoprene with indazoles is demonstrated. Under Pd-hydride catalysis,t he 1,2-or 4,3insertion pathway with respect to the electrophilic sites on isoprene could be controlled by the choice of ligands.Interms of the nucleophilic sites on indazoles,t he reaction occurs at either the N 1-o rN 2-position of indazoles is governed by the acid co-catalysts.P reliminary experimental studies have been performed to rationalizet he mechanism and regioselectivity. This study not only contributes ap ractical tool for selective functionalization of isoprene,b ut also provides ag uide to manipulate the regioselectivity for the N-functionalization of indazoles.

Through the formation of the thermodynamically favored Cr(III)−O bond, the Nozaki−Hiyama−Kishi reaction has been widely applied in the functionalization of carbonyl compounds with the help of Ni catalysis. Herein, a divergent regio-and stereoselective diarylation of dienes has been developed under Ni/Cr cocatalysis without the inherent driving force for the formation of polar metal alkoxides. Preliminary experimental studies have been conducted to elucidate the key roles of Ni, Cr, and redox-active bis(imino)pyridine (PDI) ligands. The proposed mechanism suggests that the newly formed C−C bond of this diarylation was created by organonickel species instead of organochromium species.

A systematic study shows that carbon nanotubes (CNTs) with tunable lengths can be obtained by a simple two-step electrochemical approach via oxygen defect engineering. The preoxidation of CNTs in the H2SO4 electrolyte controllably introduces oxygen defects onto the sp2-hybrid carbon skeleton. This is the key to high-efficiency tailoring of the CNTs with different length distributions (i.e., ∼640, ∼308, and ∼130 nm) by the following oxidation in NaOH electrolyte. In addition, the short-cut CNTs are free of metal impurities and destructive damage to their tubular structures, displaying excellent dispersibility in various solvents. This nondestructive cutting and purification strategy is a low-cost robust pathway to the scalable manufacturing of length-selective CNTs for various practical applications.

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Developing efficient strategies to realize divergent arylation of dienes has been a long-standing synthetic challenge. Herein, a nickel catalyzed divergent Mizoroki–Heck reaction of 1,3-dienes has been demonstrated through the regulation of ligands and additives. In the presence of Mn/NEt3, the Mizoroki–Heck reaction of dienes delivers linear products under Ni(dppe)Cl2 catalysis in high regio- and stereoselectivities. With the help of catalytic amount of organoboron and NaF, the use of bulky ligand IPr diverts the selectivity from linear products to branched products. Highly aryl-substituted compounds can be transformed from dispersive Mizoroki–Heck products programmatically. Preliminary experimental studies are carried out to elucidate the role of additives.

The catalytic bis-allylation of alkynes is an important but challenging protocol to construct all-carbon tetrasubstituted alkenes. Particularly, the catalytic unsymmetrical bis-allylation of alkynes remains as an underexplored task to date. We herein report an unprecedented unsymmetrical bis-allylation by simultaneously utilizing electrophilic trifluoromethyl alkene and nucleophilic allylboronate as the allylic reagents. With the aid of robust Ni 0 /NHC catalysis, valuable skipped trienes can be obtained in high regio-and stereo-selectivities under mild conditions. Mechanistic studies indicate that the reaction may proceed through a β-fluorine elimination of a nickelacycle followed by a transmetalation step with allylboronate. The present method exhibits a good tolerance of various functional groups. Besides, the skipped triene products can undergo an array of elaborate transformations, which highlights the potential applications of this strategy.

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