This cover picture depicts diversified halogenated secondary metabolites derived from marine microorganisms, while the chlorinated and brominated ones are the two predominant categories. These halogenated compounds with promising bioactivities and good drugability would shed light on the research and development of new candidate drugs. More details are given in the article by Luo et al. on page 1729–1750.

This cover picture discribes an efficient three-component [3+2+1] cycloaddition of simple alkenes with two C—H substrates via oxidative dicarbofunctionalization/cyclization sequence. The reaction involves the formation of two C—C bonds and one C—O bond through the cleavage of three C—H bonds in a single operation and a variety of functionalized chromenes were obtained in good yields. More details are given in the article by Liu et al. on page 1681–1686.

A protecting-group-free palladium-catalyzed allylic coupling of natural product cucurbitacin B with boronic acids was developed, providing a one-step approach to expand the chemical diversity of the C25 position of cucurbitacin B. A library of 29 derivatives was prepared, some of the compounds showed higher cytotoxicity against A549 cells than cucurbitacin B.

A novel copper-catalyzed 1,2,5-trifunctionalization of terminal alkynes is realized by using a traceless directing hydrogen atom transfer strategy, providing a direct access to highly functionalized aldehydes that are otherwise diffcult to access from feedstock chemicals.

A novel kinetic resolution (KR) protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis. Notably, 1,2-diamines bearing both α-secondary and α-tertiary amine moieties are compatible with this method, which gave good to high KR performances (with s-factor up to 218).

An efficient three-component [3 + 2 + 1] cycloaddition of simple alkenes with benzoquinones and dicarbonyl compounds via oxidative dicarbofunctionalization/cyclization sequence has been reported. The copper-catalyzed intermolecular dicarbofunctionalization/cyclization of alkenes proceeds smoothly with two C—H reagents and a variety of functionalized chromenes are obtained involving the formation of two C—C bonds and one C—O bond through the cleavage of three C—H bonds in a single operation.

Herein, we report the first method for electrochemical synthesis of sulfonyl fluorides with triethylamine hydrofluoride as a fluorine source. These electricity-driven reactions of odorless sulfinic salts were carried out under oxidant-free conditions. Aryl, aliphatic, and alkenyl sulfonyl fluorides could be accessed by means of this method. In addition, we report a one-pot protocol for Pd-catalyzed C—S cross-coupling and oxidative fluorination under electrochemical conditions. A reaction pathway involving the supporting electrolyte is proposed.

A copper-catalyzed asymmetric trifluoromethyl-alkynylation of α-aryl substituted acrylamides was developed, which provides a straightforward and efficient access to chiral quaternary all-carbon centers bearing alkynyl groups in good yields and enantioselectivities.

This review article summarizes the recent progress on responsive polymer composite fibers, with a focus on chromatic and deformational fibers.

This review describes the developments in the automated chemical solid-phase synthesis of glycans, with the initial discovery and major breakthroughs in Automated Glycan Assembly being highlighted.

This review aims to summarize the chemistry, biosynthesis, and biological activity of 316 halogenated compounds isolated from marine microorganisms (2015—May 2021). These halogenated compounds originated from 36 genera of fungi (62%) and 9 bacterial strains (38%) were found with diverse structures (polyketides, alkaloids, phenols, and others) and significant bioactivities (cytotoxic, antibacterial, and enzyme inhibitory).

The development of innovative methods capable of overriding the “inherent” site-selectivity in radical-mediated sp³ C—H functionalization is exceedingly attractive and will have important impacts on synthesis. However, the selective activation of unactivated primary C—H bonds remains a daunting challenge. In this Emerging Topic, we highlight the recent advances towards this goal by tuning the steric properties of hydrogen atom acceptors.

The Inside back cover picture shows an unprecedented copper-catalyzed 1,2,5-trifunctionalization of terminal alkynes, which is realized through synergetic hydrogen atom transfer and traceless directing strategy with SR as the transient group. This work features high efficiency of installing three different functional groups in a single reaction, furnishing a wide array of polyfunctionalized aldehydes that are otherwise difficult to access with excellent functional group compatibility. Given its unique advantages, this method will be valuable in rapidly assembling complex molecules from readily available starting materials. More details are given in the article by Zhu et al. on page 1667–1673.

The back cover picture shows a protecting-group-free palladium-catalyzed allylic coupling of cucurbitacin B, a natural product mainly found in cucurbitaceous plants. This convenient method provided a one-step approach to expand the chemical diversity of the C25 site of cucurbitacin B. Some of the compounds showed higher cytotoxicity against A549 cells than cucurbitacin B. More details are discussed in the article by Nan et al. on page 1662–1666.