From 2000 to mid-2010: a fruitful decade for the synthesis of pyrazoles.

1,3,4-Thiadiazole: Synthesis, Reactions, and Applications in Medicinal, Agricultural, and Materials Chemistry

Sulfoxaflor and the sulfoximine insecticides: Chemistry, mode of action and basis for efficacy on resistant insects

1,4,2-Dioxazol-5-ones are five-membered heterocycles known to decarboxylate under thermal or photochemical conditions, thus yielding N-acyl nitrenes. Described herein is a light-induced ruthenium-catalyzed N-acyl nitrene transfer to sulfides and sulfoxides by decarboxylation of 1,4,2-dioxazol-5-ones at room temperature, thus providing direct access to N-acyl sulfimides and sulfoximines under mild reaction conditions. In addition, a one-pot sulfur imidation/oxidation sequence catalyzed by a single ruthenium complex is reported.

Light‐Induced Ruthenium‐Catalyzed Nitrene Transfer Reactions: A Photochemical Approach towards N‐Acyl Sulfimides and Sulfoximines

immense usefulness of 3-trifluoromethylpyrazole derivatives, efficient construction of the 3-trifluoromethylpyrazole framework has become the subject of intensive research in the fields of synthetic and medicinal chemistry. Generally, 3-trifluoromethylpyrazoles can be accessed by cyclocondensations of an appropriate hydrazine with the corresponding 1,3-dicarbonyl compounds. However, these methods often suffer from the formation of regioisomeric mixtures with respect to substituents incorporated at the 3and 5-positions of the pyrazole ring. Recently, 2,2,2-trifluorodiazoethane has emerged as an attractive synthon in transition-metal-catalyzed/mediated and organocatalytic reactions for the construction of fluorinecontaining building blocks. In this regard, Morandi, Carreira, and co-workers disclosed a rhodium-catalyzed cyclopropenation of alkynes with CF3CHN2 generated in situ from CF3CH2NH2·HCl in aqueous media, [6b] and we developed the copper(I)-catalyzed cross-coupling of terminal alkynes and gaseous CF3CHN2, thus leading to the formation of C H insertion products (Scheme 1, top). These reactions

Silver-Mediated Cycloaddition of Alkynes with CF3CHN2: Highly Regioselective Synthesis of 3-Trifluoromethylpyrazoles†

A series of novel pyrazole oxime derivatives containing a 2-chloro-5-thiazolyl moiety were synthesized. Their structures were confirmed by (1)H NMR, (13)C NMR, and elemental analysis. The preliminary bioassays showed that all of the title compounds had low acaricidal activity against Tetranychus cinnabarinus . However, most of them exhibited excellent insecticidal activity against Aphis medicagini at the dosage of 0.5 mg/mL, and some compounds still showed good insecticidal activity against A. medicagini even at the dosage of 0.2 mg/mL. Meanwhile, some title compounds displayed fungicidal and plant growth regulatory activities.

Synthesis and Biological Activities of Novel Pyrazole Oxime Derivatives Containing a 2-Chloro-5-thiazolyl Moiety

The N-substituted alkyl sulfoximine derivatives are a new chemical family of neonicotinoid insecticides. We have designed and synthesized 10 (1,3-thiazole)alkyl sulfoximine derivatives. All compounds were identified by (1)H and (13)C nuclear magnetic resonance (NMR), IR, and elemental analyses. Preliminary bioassays indicated that some title compounds exhibited good insecticidal activities at 10 mg/L against Myzus persicae . The relationship between structure and biological activity was also discussed.

Synthesis and insecticidal activity of N-substituted (1,3-thiazole)alkyl sulfoximine derivatives.

Three series of novel 2-cyanoacrylates 7a–7f, 9a–9f, 10a–10f containing 1,3,4-thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II (PS II) electron transportation. Their structures were clearly verified by 1H NMR, 13C NMR, elemental analysis (or HRMS analysis) and single-crystal X-ray diffraction analysis. Bioassay showed that a suitable group at the 3-position of acrylates was essential for high herbicidal activity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5-position of 1,3,4-thiadiazole decreased herbicidal activities.

Xin Zhang

Papers

Synthesis and Biological Activities of Novel Pyrazole Oxime Derivatives Containing a 2-Chloro-5-thiazolyl Moiety

Synthesis and insecticidal activity of N-substituted (1,3-thiazole)alkyl sulfoximine derivatives.

Synthesis, Crystal Structure, and Herbicidal Activities of 2‐Cyanoacrylates Containing 1,3,4‐Thiadiazole Moieties

Synthesis and herbicidal activities of 2-cyano-3-benzylaminoacrylates containing thiazole moiety.

Synthesis, Crystal Structure, and Herbicidal Activities of 2-Cyanoacrylates Containing 1,3,4-Thiadiazole Moieties.