The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C–C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of...

Advances in Synthetic Applications of Hypervalent Iodine Compounds

10. Patented Literature 2616 10.1. Esterification 2616 10.2. Ether Formation 2619 10.2.1. Etherification without Cyclization 2619 10.2.2. Etherification with Cyclization 2624 10.3. N-Alkylation 2625 10.4. Other Reactions 2627 11. Summary and Outlook 2628 12. Note Added in Proof 2628 13. Abbreviations Used in This Review 2629 14. Acknowledgments 2629 15. Supporting Information Available 2630 16. References 2630

Mitsunobu and Related Reactions: Advances and Applications

Research and industrial interest in radical C–H activation/radical cross-coupling chemistry has continuously grown over the past few decades. These reactions offer fascinating and unconventional approaches toward connecting molecular fragments with high atom- and step-economy that are often complementary to traditional methods. Success in this area of research was made possible through the development of photocatalysis and first-row transition metal catalysis along with the use of peroxides as radical initiators. This Review provides a brief and concise overview of the current status and latest methodologies using radicals or radical cations as key intermediates produced via radical C–H activation. This Review includes radical addition, radical cascade cyclization, radical/radical cross-coupling, coupling of radicals with M–R groups, and coupling of radical cations with nucleophiles (Nu).

Recent Advances in Radical C-H Activation/Radical Cross-Coupling.

Carbon trifluoromethylation reactions of hydrocarbon derivatives and heteroarenes.

Nucleophilic phosphine catalysis has proven to be a powerful tool in organic synthesis, which can provide easy access to cyclic, bicyclic or polycyclic carbocycles and heterocycles. Owing to their comparatively strong and readily tunable nucleophilicity, phosphines can be easily tailored to efficient annulation reactions with good control over reaction selectivity. This has resulted in a tremendous increase in their scope and in a concomitant number of reports where phosphine-triggered annulation reactions occur. This tutorial review summarizes the recent achievements in this area.

Phosphine-triggered synthesis of functionalized cyclic compounds

On the basis of the structures of chlorfenapyr and dioxapyrrolomycin, a series of 2-benzylpyrroles with a hydroxyl, an alkyloxy, an acyloxy, an alkylsulfanyl, or an oxime moiety at the α-position of benzyl were designed and synthesized. Their insecticidal, acaricidal, and fungicidal activities were extensively investigated. The structure–activity relationship showed that benzylpyrroles bearing shorter α-alkyloxy groups gave better activities against most of the insect species; the alkylation of pyrrole usually gave increased activity. Among all compounds, (4-bromo-2-(α-(2,2,2-trifluoroethoxy)-4-chlorobenzyl)-1-(ethoxymethyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile) (5′j) exhibited the most outstanding insecticidal activities against oriental armyworm (IC50 = 10 mg L–1), diamondback moth (0.07 mg L–1), corn borer (50 mg L–1), and mosquito (0.04 mg L–1), which are very close to those of chlorfenapyr (5, 0.08, <25, and <0.025 mg L–1, respectively). In addition, some compounds also exhibited a broad or ...

Design, synthesis, and biological evaluation of various α-substituted benzylpyrroles based on the structures of insecticidal chlorfenapyr and natural pyrrolomycins.

Synthesis of Functionalized Spirocyclic Indolines by Visible Light-Induced One-Pot Sequential Difluoromethylative Dearomatization, Hydroxylation, and Substitution Reactions

Herein, we report a mild protocol for metal-, photocatalyst-, and light-free Minisci C-H alkylation reactions of N-heteroarenes with alkyl oxalates derived from primary, secondary, and tertiary alcohols. The protocol uses environmentally benign persulfate as a stoichiometric oxidant and does not require high temperatures or large excesses of either of the substrates, making the procedure suitable for late-stage C-H alkylation of complex molecules. Notably, several pharmaceuticals and natural products could be functionalized or prepared with this protocol, thus demonstrating its utility.

Metal-, Photocatalyst-, and Light-Free Minisci C-H Alkylation of N-Heteroarenes with Oxalates.

Based on the structures of the 4-hydroxyphenylpyruvate dioxygenase inhibitor mesotrione and natural product fischerellin A, a series of imine derivatives of (E)-3-acyl-quinoline-2,4(1H,3H)-dione (6, 12 and 16) were designed, synthesized and systematically evaluated for their herbicidal activity. The bioassay results indicated that most of the synthesized compounds displayed good to excellent herbicidal activity, of which 6e, 6g, 6h, 6q and 6t exhibited more than 50 % inhibition against Brassica napus L., Amaranthus retroflexu or Digitaria adscendens at a dosage of 94 g ha−1 or lower. The symptom of injured leaves in vivo, the high Hill reaction inhibitory activity of 6h in vitro(IC50 0.1μgmL−1) and the computer-based binding model of compound 6h with D1 protein in photosystem II (PSII) reaction centre suggest this novel structure to likely be a new type of PSII electron transport inhibitor. Thus, we have found a novel type of diketone enamine structure targeted at the PSII reaction centre.

The discovery of 3-(1-aminoethylidene)quinoline-2, 4(1H,3H)-dione derivatives as novel PSII electron transport inhibitors

On the basis of the interaction of antofine and tobacco mosaic virus (TMV) RNA, a series of phenanthrene and alkylamine chain containing antofine derivatives 1–41 were designed, synthesized, and systematically evaluated for their antiviral activity against TMV. The results showed that most of these compounds exhibited good to excellent anti-TMV activity, which indicated that the D and E rings of antofine may not be indispensable. Phenanthrene is important for these compounds, but not the more the better. Phenanthrene, benzene rings, and alkylamine chain containing compounds exhibited good antiviral activity. The optimum compounds, 10, 18, and 19, displayed higher activity than precursor antofine and commercial ribavirin, thus emerging as new lead compounds. The novel concise structure provides another new template for antiviral studies.

D and E rings may not be indispensable for antofine: discovery of phenanthrene and alkylamine chain containing antofine derivatives as novel antiviral agents against tobacco mosaic virus (TMV) based on interaction of antofine and TMV RNA.

Yuxiu Liu

Papers

Design, synthesis, and biological evaluation of various α-substituted benzylpyrroles based on the structures of insecticidal chlorfenapyr and natural pyrrolomycins.

Synthesis of Functionalized Spirocyclic Indolines by Visible Light-Induced One-Pot Sequential Difluoromethylative Dearomatization, Hydroxylation, and Substitution Reactions

Metal-, Photocatalyst-, and Light-Free Minisci C-H Alkylation of N-Heteroarenes with Oxalates.

The discovery of 3-(1-aminoethylidene)quinoline-2, 4(1H,3H)-dione derivatives as novel PSII electron transport inhibitors

D and E rings may not be indispensable for antofine: discovery of phenanthrene and alkylamine chain containing antofine derivatives as novel antiviral agents against tobacco mosaic virus (TMV) based on interaction of antofine and TMV RNA.