Jie Feng

Bio: Jie Feng is an academic researcher from China Pharmaceutical University. The author has contributed to research in topics: Enantioselective synthesis & Carbonylation. The author has an hindex of 6, co-authored 12 publications receiving 76 citations.

Generation of azolium dienolates as versatile nucleophilic synthons via N-heterocyclic carbene catalysis

Abstract: N-Heterocyclic carbene (NHC) organocatalysis has emerged as a powerful tool in the field of modern organic synthesis especially in asymmetric construction of various cyclic skeletons. As emerging NHC-bound nucleophilic intermediates, azolium dienolates have been widely investigated and applied in NHC-catalyzed transformations due to their unique reactivities and versatile structures. Particularly, four representative kinds of reactive azolium dienolates (I–IV) have been explored as versatile nucleophilic synthons via either α-functinalization or remote γ-functionalization to achieve efficient construction of complex skeletons. Moreover, these NHC-bound intermediates had wide-ranging applications in asymmetric synthesis of diversely enantioenriched centrally chiral molecules. In this review, the recent advances in NHC-catalyzed generation of azolium dienolates from different precursors and their applications in the synthesis of various valuable molecules are summarized comprehensively.

Photochemical and Electrochemical Applications of Proton-Coupled Electron Transfer in Organic Synthesis.

Abstract: We present here a review of the photochemical and electrochemical applications of multi-site proton-coupled electron transfer (MS-PCET) in organic synthesis. MS-PCETs are redox mechanisms in which both an electron and a proton are exchanged together, often in a concerted elementary step. As such, MS-PCET can function as a non-classical mechanism for homolytic bond activation, providing opportunities to generate synthetically useful free radical intermediates directly from a wide variety of common organic functional groups. We present an introduction to MS-PCET and a practitioner's guide to reaction design, with an emphasis on the unique energetic and selectivity features that are characteristic of this reaction class. We then present chapters on oxidative N-H, O-H, S-H, and C-H bond homolysis methods, for the generation of the corresponding neutral radical species. Then, chapters for reductive PCET activations involving carbonyl, imine, other X═Y π-systems, and heteroarenes, where neutral ketyl, α-amino, and heteroarene-derived radicals can be generated. Finally, we present chapters on the applications of MS-PCET in asymmetric catalysis and in materials and device applications. Within each chapter, we subdivide by the functional group undergoing homolysis, and thereafter by the type of transformation being promoted. Methods published prior to the end of December 2020 are presented.

Photoinduced Borylation for the Synthesis of Organoboron Compounds.

Abstract: Organoboron compounds have important synthetic value and can be applied in numerous transformations. The development of practical and convenient ways to synthesize boronate esters has thus attracted significant interest. Photoinduced borylations originated from stoichiometric reactions of alkanes and arenes with well-defined metal-boryl complexes. Now, photoredox-initiated borylations, catalyzed by either transition metal or organic photocatalysts, and photochemical borylations with high efficiency have become a burgeoning area of research. In this Focus Review, we summarize research on photoinduced borylations, especially emphasizing recent developments and trends. This includes the photoinduced borylation of arenes, alkanes, aryl/alkyl halides, activated carboxylic acids, amines, alcohols, and so on based on transition metal catalysis, metal-free organocatalysis, and direct photochemical activation. We focus on reaction mechanisms involving single-electron transfer, triplet-energy transfer, and other radical processes.

Synthetic Applications of Sulfonium Salts

Abstract: This minireview aims to cover the developments over the past two decades in the chemistry of sulfonium salts. Specifically, insight is provided into the synthetic strategies available for the preparation of these compounds, the different reactivity patterns that are expected depending on their structural features or the reaction conditions applied, and the diversity of organic scaffolds that can thereby be synthesized. Additionally, the pros and cons derived from the use of sulfonium salts are presented and critically compared, when possible, in relation to reagents not based on sulfur but depicting similar reactivity.

Carbene-Catalyzed Asymmetric Construction of Atropisomers.

Abstract: Atropisomeric molecules have found proven applications and promising potentials in chemistry and medicines. The design of N-heterocyclic carbene (NHC)-catalyzed reactions in constructing atropisomerically enriched molecules emerged as an important research topic in recent years. These reactions include kinetic resolutions, asymmetric desymmetrizations, central-to-axial chirality conversions, and cycloadditions. This review evaluates and summarizes the progress on NHC organic catalysis for access to atropisomers, and briefly states our personal perspectives on the future advancement of this direction. NHC catalysis has provided rich and unique reaction modes with numerous success in asymmetric synthesis of central chiral molecules. It is expected that similar success can also be achieved in developing NHC catalysis to prepare atropisomeric molecules, including those not easily accessible with other methods. Readers in the broadly defined community of chemistry shall find this review as a valuable source for information and hopefully inspirations.