Ni-soc-MOF derived carbon hollow sphere encapsulated Ni3Se4 nanocrystals for high-rate supercapacitors.

Carbon hollow sphere encapsulated Ni3Se4 (Ni3Se4@CHS) nanocrystals are prepared using the Ni-soc-MOF by pyrolysis and further selenization. Ni3Se4@CHS exhibits a capacitance of 1720 F g-1 at 1 A g-1 and a capacitance retention of 97% after 6000 cycles at 5 A g-1. Moreover, the asymmetric supercapacitor of Ni3Se4@CHS//AC displays a wide potential window of 1.6 V, an energy density of 45.2 W h kg-1 at a power density of 800 W kg-1, and excellent cycling stability (89% capacitance retention) after 5000 cycles. Overall, this work establishes a significant step to synthesize a new carbon-based material with appreciable capacitance and long cycling durability for potential applications in energy storage and beyond.

Synthesis of cyclobutane-fused oxygen-containing tricyclic framework via thermally promoted intramolecular cycloaddition of cyclohexadienone-tethered allenes.

We have developed a unique approach for the thermally promoted cycloaddition of cyclohexadienone-tethered allenes to form a versatile cyclobutane-fused oxygen-containing tricyclic framework in an environmentally friendly and atomic economic fashion with high regioselectivity. The reaction encompasses a broad substrate scope and functional group tolerance of cyclohexadienone moieties. Moreover, the cycloaddition was also applicable to the late-stage functionalization of pharmaceutically relevant compounds.

Synthesis of tetrasubstituted thiophenes via a [3+2] cascade cyclization reaction of pyridinium 1,4-zwitterionic thiolates and activated allenes.

A [3+2] cascade cyclization reaction of pyridinium 1,4-zwitterionic thiolates and activated allenes has been developed, which allows facile access to a library of tetrasubstituted thiophenes with great variety under thermal conditions.

One-pot synthesis of benzo[b]fluorenones via a cobalt-catalyzed MHP-directed [3+2] annulation/ring-opening/dehydration sequence.

We have developed a one-pot synthesis of benzo[b]fluorenones via a cobalt-catalyzed [3+2] annulation of oxabicyclic alkenes followed by a ring-opening/dehydration sequence in good to excellent yields. With the use of 2-(1-methylhydrazinyl)pyridine (MHP), first explored by our group as the bidentate directing group in C-H functionalization of benzoic hydrazides, the new reaction sequence proceeded smoothly and tolerated a wide range of functional groups, featuring facile scalability. Notably, oxygen served as the green oxidant in the reaction system. Careful tuning of the reaction parameters assured the direct synthesis of benzo[b]fluorenones through aromatization of the dihydroepoxybenzofluorenone intermediate.

A 2-(1-methylhydrazinyl)pyridine-directed C-H functionalization/spirocyclization cascade: facile access to spirosuccinimide derivatives.

A cobalt-catalyzed oxidative coupling of benzoic hydrazides with maleimides by utilizing 2-(1-methylhydrazinyl)pyridine as a bidentate directing group has been developed. This C-H functionalization/spirocyclization cascade protocol shows high efficiency and remarkable functional group tolerance, and the ubiquitous spirosuccinimides were obtained in good to excellent yields with high regioselectivity. This strategy also provides a novel and efficient access to diverse symmetric and unsymmetrical bisspirosuccinimides.

2-(1-Methylhydrazinyl)pyridine as a reductively removable directing group in a cobalt-catalyzed C(sp2)-H bond alkenylation/annulation cascade.

We describe a new application of 2-(1-methylhydrazinyl)pyridine as a bidentate directing group to directing cobalt-catalyzed C(sp2)-H alkenylation/annulation of the corresponding benzoic hydrazides to form an isoquinoline backbone, via reacting with a terminal or internal alkyne followed by annulation. The reaction shows a broad substrate scope with the products obtained in good to excellent yields and high regioselectivity. Moreover, the directing group can be reductively removed in one step under mild conditions.

Asymmetric Total Synthesis of (-)-Aspidophylline A.

An asymmetric total synthesis of (-)-aspidophylline A has been accomplished. The key transformations include an asymmetric hydride transfer hydrogenation of an α,ß-acetylenic ketone and a cationic gold(I)-catalyzed 6-exo-dig cyclization involving an alkynylindole/aminal formation cascade, which enables stereoselective establishment of the requisite quaternary carbon center.