Abstract2‐Propargyl alcohols are widely used in organic reactions. Their great success is rooted in the presence of multiple functional groups. This review will focus on six types of mechanisms: (i) 2‐propargyl alcohols as carbocation precursors, (ii) alkynes as electrophiles, (iii) alcohols as nucleophiles, (iv) fracture via ketones or elimination into alkene intermediates, (v) oxidation into alkynyl‐ortho‐quinone methides or carbonyl intermediates, and (vi) ring expansions. Reactions involving alkanes, alkenes, alkynes, arenes, alcohols, amines, amides, ketones, CO2, hydrazine, iodobenzene, azides, carbenes, arylboronic acids, etc. will be discussed. We hope that this review will help to promote future research in this area.magnified image

HIGHLIGHTS • 3D hierarchical conductive Sn quantum dots encapsulated in N,S co-doped carbon nanofibers sheathed within rGO scrolls (Sn/NS-CNFs@rGO) were prepared through an electrospinning process. • Flexible Sn/NS-CNFs@rGO electrode exhibits superior long-term cycling stability and high-rate capability in sodium-ion batteries. ABSTRACT Metallic Sn has provoked tremendous progress as an anode material for sodium-ion batteries (SIBs). However, Sn anodes suffer from a dramatic capacity fading, owing to pulverization induced by drastic volume expansion during cycling. Herein, a flexible three-dimensional (3D) hierarchical conductive network electrode is designed by constructing Sn quantum dots (QDs) encapsulated in one-dimensional N,S codoped carbon nanofibers (NS-CNFs) sheathed within two-dimensional (2D) reduced graphene oxide (rGO) scrolls. In this ingenious strategy, 1D NS-CNFs are regarded as building blocks to prevent the aggregation and pulverization of Sn QDs during sodiation/desodiation, 2D rGO acts as electrical roads and "bridges" among NS-CNFs to improve the conductivity of the electrode and enlarge the contact area with electrolyte. Because of the unique structural merits, the flexible 3D hierarchical conductive network was directly used as binder-and current collectorfree anode for SIBs, exhibiting ultra-long cycling life (373 mAh g −1 after 5000 cycles at 1 A g −1), and excellent high-rate capability (189 mAh g −1 at 10 A g −1). This work provides a facile and efficient engineering method to construct 3D hierarchical conductive electrodes for other flexible energy storage devices.

Scheme 12. Enamines:T BAF-catalyzed cyclization.Scheme 13. Intramolecular cyclization.Scheme14. Intramolecular cyclizations.Scheme15. CÀNa nd OÀNb ond cleavage. Scheme 16. Applications of RNH-Nu. Scheme 17. NH-sulfoximines and NH-sulfondiimines. Scheme18. Radical cyclizationf or the synthesis of indoles. Scheme 22. 2H-Azirines:[3 + +2] cycloadditions. Scheme 23. Visible light-induced cycloaddition for pyrrole synthesis. Scheme24. Cyclization and sulfonyl migration. Scheme 25. NR 2 -E strategy analysis. Scheme 57. Several arenes for annulations. Scheme 58. Conjugateaddition. Scheme 59. Asymmetric conjugate addition.Scheme60. Conjugatea ddition andcyclization.

Aryl diazonium salts are important molecules in organic chemistry. This review discusses advances of their application in light‐mediated reactions summarized in five categories according to the bond formations: (1) C−C formation from alkenes, alkynes, arenes, isocyanide, CO, arylboronic acid, or Grignard reagent. (2–5) C−B, C−N, C−S, and C−P formations. Reactions such as radical addition, elimination, metal‐catalyzed coupling, C−H activation, cyclizations, and rearrangements will be discussed herein.

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