Xueshun Jia

A rearrangement of propargylic pivalate with isocyanide under transition metal‐free conditions is disclosed. Intermolecular 1,3‐acyloxy and acyl migration enables the rapid formation of a C(sp²)−C(sp³) bond from a C−O bond and the synthesis of polysubstituted 5‐iminopyrrolones. magnified image

Conformational exchanges of synthetic macrocyclic acceptors are rather fast, which is rarely studied in the absence of guests. Here, we report multiple stimuli-responsive conformational exchanges between two preexisting conformations of 2,2′,4,4′-tetramethoxyl biphen[3]arene (MeBP3) macrocycle. Structures of these two conformations are both observed in solid state, and characterized by ¹H NMR, ¹³C NMR and 2D NMR in solution. In particular, conformational exchanges can respond to solvents, temperatures, guest binding and acid/base addition. The current system may have a role to play in the construction of molecular switches and other stimuli-responsive systems.

Palladium-catalyzed cascade reactions of enynones and isocyanides have been disclosed, which enable the synthesis of furan-incorporated ketenimines.

α,β-Unsaturated phosphine sulfides may exhibit different reactivity from α,β-unsaturated phosphine oxides toward nucleophilic addition and thus may find new applications in copper(I)-catalyzed asymmetric reactions. Herein, various α,β-unsaturated phosphine sulfides were prepared in moderate to excellent yields from the parent α,β-unsaturated phosphine oxides with Lawesson’s reagent. The reaction enjoys a broad substrate scope and tolerates a variety of functional groups.

^§ These authors contributed equally to this work. A novel oxidative esterification of 1-arylprop-2-en-1-ols with toluene derivatives catalyzed by tetrabutylammonium iodide (TBAI) is reported. The optimization of the reaction conditions illustrates that each of experiment parameters including the catalyst, solvent, and oxidant is significant for present oxidative functionalization. This metal-free protocol has a broad substrate scope including the halogen groups for further functionalization and enriches the reactivity profile of allyl alcohol and toluene derivatives. In addition, this protocol represents a new transformation of allyl alcohol involving C–C bond cleavage and C–O bond forming.

A novel bicyclization reaction of two molecular allenyl ketones and isocyanides has been disclosed. This strategy allows for the construction of structurally complex spirocyclic lactam–lactone systems in an efficient manner.

A DABCO-catalyzed annulation reaction of pyridin-2-amine and substituted allenoates enables the ring-opening of a pyridine ring system and the formation of two new rings including a pyrimidinone ring and a benzene ring.

A new strategy for supramolecular polymerization is designed and presented, which is based on the wheel-stopper charge-transfer interactions of [2]rotaxanes.

This review summarizes recent developments in the field of copper-mediated or -catalyzed C–H functionalization. The substrate scope has been expanded from the C–H activation of aryls to more challenging alkyls. Furthermore, catalytic amounts of copper salt are sufficient to promote the challenging C–H functionalization in some cases, which represents the focus of future research.1 Introduction2 C–C Bond Formation3 C–N Bond Formation4 C–O Bond Formation5 C–Halogen Bond Formation6 C–S Bond Formation7 Conclusions and Outlook