Divergent synthesis is extremely important for the highly efficient preparation of structurally diverse target molecules. Herein, we describe a multicomponent cascade reaction, which allows access to highly substituted pyridines and benzenes by combining four individual steps in a one-pot manner from the same set of readily available starting materials. The azepine intermediates were first used as the precursors for 6π-electrocyclization to construct highly substituted pyridines and benzenes in a tunable manner.

The construction of benzylic all-carbon quaternary stereocenters, which are ubiquitous in biomolecules and drugs, is a task of high practical significance. Herein, we disclose a highly efficient one-pot method of constructing all-carbon quaternary structural units from aryl ketones, revealing that the entire process involves three consecutive chemical events, namely nucleophilic addition, Meinwald 1,2-hydrogen migration, and alkylation. Interestingly, dimerization of acetophenones results in formation of 2,4-diarylfurans under the employed conditions rather than the quaternary carbon products.

A cascade 8π electrocyclization/benzannulation reaction was developed to obtain the synthetically important highly substituted phenyl-pyridines. This method shows great potential in the rapid and inexpensive application of the scalable and operationally simple production of accessible substrates. On the basis of the resulting phenyl-pyridine products, a new Ru catalyst and bidentate ligand were designed and prepared, further demonstrating its high practicability.

We describe a novel triazole-phosphine Pd(II) (TPP) complex-catalyzed dehydrogenation reaction of alcohols or amines by using iodobenzene as the oxidant, in which a unique butterfly TPP dimer is first prepared via a three-component reaction of 1,2,3-triazole, P(Cy) 3 , and PdCl 2 and the competitive cross-coupling reaction of iodobenzene with alcohols or amines could be avoided under TPP catalysis. In particular, the primary alcohols and imines can be further oxidized into acids or nitriles in a tunable manner, respectively. Preliminary mechanistic results by density functional theory calculation suggest that this reaction follows the Pd(II)−Pd(IV) catalytic pathway and the process of TPP-catalyzed oxidation dehydrogenation of alcohol or amine to form unsaturated bonds and Pd(II)−H species generated before the oxidative addition of TPP with iodobenzene, thereby avoiding competitive cross-coupling.

Nitrogen-containing heterocycles are the key components in many pharmaceuticals and functional materials. In this study, we reported a transition metal-catalyzed high-order reaction sequence for synthesizing a structurally unique N-center 5,6,7-perifused cycle (NCPC). The key characteristics included the formation of a seven-membered ring by the 8π electrocyclization of various alkenes and aromatic heterocycles as π-components, in which metal carbene species generated that further induced the cleavage of the α-C-H or -C-C bond. Specifically, the latter could react with various nucleophilic reagents containing -O, -S, -N, and -C. The stereo-controlled late-stage modification of some complicated pharmaceuticals indicated the versatility of this protocol.