Diastereoselective Synthesis of Z‐Alkenyl Disulfides from α‐Thiophosphorylated Ketones and Thiosulfonates

Electrochemical Activation of the C-X Bond on Demand: Access to the Atom Economic Group Transfer Reaction Triggered by Noncovalent Interaction

An atom economic method demonstrates the involvement of noncovalent interaction via hydrogen or halogen bonding interaction in triggering paired electrolysis for the group transfer reactions. Specifically, this method demonstrated the bromination of several aromatic and heteroaromatic compounds through the activation of the C(sp³)-Br bond of organic-bromo derivatives on demand. This electrochemical protocol is mild, and mostly no additional electrolyte is needed, which makes the workup process straightforward. Unlike the existing regioselective monobromination methods, this work utilizes a relatively small amount (1.2 equiv) of bromine surrogates that releases bromine on demand under the electrochemical condition and after completion of the reaction generates acetophenone as a useful byproduct. Green metrics indicate this protocol has a very good atom efficiency with an E-factor of 26.86 kg of waste/1 kg of product. In addition to the scale-up process, this strategy could be extended to the transfer of chlorine and thioaryl units. An extensive mechanistic study is accomplished to validate the hypothesis of noncovalent interaction using computational, spectroscopic, and cyclic voltammetry studies. Finally, the applicability of this newly developed nonbonding interaction to trigger paired electrolysis was extended to the chemoselective debromination of several dihalo organic compounds.

Discovery of Novel Triazolothiadiazines as Fungicidal Leads Targeting Pyruvate Kinase

Pyruvate kinase (PK) was discovered as a potent new target for novel fungicide development. A series of novel triazolothiadiazine derivatives were rationally designed and synthesized by a ring expansion strategy and computer-aided pesticide design using the 3D structure of Rhizoctonia solani PK (RsPK) obtained by homology modeling as a receptor and our previously discovered lead YZK-C22 as a ligand. The in vitro bioassay results indicated that compounds 4g, 6h, 6m, 6n, 6o, and 6p exhibited good activity against R. solani with the EC₅₀ values falling between 10.99 and 72.76 μM. Especially, 6m showed similar potency to YZK-C22 (10.99 vs 11.97 μM of the EC₅₀ value, respectively). The in vivo bioassay results suggested that 6m against R. solani at a concentration of 200 μg/mL displayed a numerically higher inhibition than YZK-C22 (70 vs 60%, respectively). A field experiment validated that 6m at an application rate of 120 g ai/ha showed comparable efficacy against R. solani to thifluzamide at an application rate of 80 g ai/ha (77.80 vs 84.5%, respectively). Enzymatic inhibition suggested that the potency of 6m was about twofold lower than that of YZK-C22 (67.30 vs 32.64 μM of IC₅₀, respectively). Fluorescence quenching studies validated that RsPK was quenched by both 6m and YZK-C22, implying that they both might act at the same target site of PK. A possible binding conformation of 6m in the RsPK active site was depicted by molecular docking. Our studies suggest that 6m could be a fungicidal lead targeting PK.

Convenient Synthesis of Functionalized Unsymmetrical Vinyl Disulfides and Their Inverse Electron-Demand Hetero-Diels-Alder Reaction

The simple, convenient, and efficient methods for the preparation of unsymmetrical vinyl disulfides with additional functional groups under mild conditions with moderate to high yields were designed. The developed methods include the reaction of S-vinyl phosphorodithioate with thiotosylates or S-vinyl thiotosylate with thiols. The designed methods allow for the synthesis of unsymmetrical vinyl disulfides with additional functionalities such as hydroxy, carboxy, protected amino, or ester groups. Vinyl disulfides reacted with the generated transient o-iminothioquinones in an inverse electron-demand [4+2] cycloaddition to produce benzo[b][1,4]thiazine derivatives.

Phenylboronic acid-catalyzed tandem construction of S-S and C-S bonds: a new method for the synthesis of benzyl disulfanylsulfone derivatives from S-benzyl thiosulfonates

A unique phenylboronic acid-catalyzed dimerization-sulfonylation of S-benzyl thiosulfonates has been disclosed. A metal-free tandem construction of S-S and C-S bonds is an operationally simple method to access a wide range of benzyl disulfanylsulfone derivatives in high to excellent yields. Moreover, the robustness of this tandem transformation has been demonstrated by gram-scale reactions, and a plausible mechanism is also proposed.

The synthesis of N,N′-disulfanediyl-bis(N′-((E)-benzylidene)acetohydrazide) from (E)-N′-benzylideneacetohydrazide and S8

Herein we report an oxidative coupling reaction for N–S/S–S bond formation from (E)-N′-benzylideneacetohydrazide and S₈ to furnish substituted N,N′-disulfanediyl-bis(N′-((E)-benzylidene) acetohydrazide). It provides a direct approach for the synthesis of disulfides with good yields.

Herein we report an oxidative coupling reaction for N–S/S–S bond formation substituted N,N′-disulfanediyl bis(N′-((E)-benzylidene)acetohydrazide). It provides a direct approach for the synthesis of disulfides with good yields.