Qiantao Wang

1,2,3-Triazole-assisted C–H amidation by cobalt(III) catalysis

A procedure for the [Cp*CoIII]-catalyzed, 1,2,3-triazole directed C–H amidation of arenes, using dioxazolone as an efficient amidating reagent, has been developed. This reaction provides a step- and atom-economical protocol for C–N bond formation, releasing carbon dioxide as a single byproduct. Yet a variety of functional groups are well tolerated, obtaining the desired products in moderate to excellent yields.

Palladium-catalyzed direct C–H ethoxycarbonylation of 2-aryl-1,2,3-triazoles and efficient synthesis of suvorexant

Efficient palladium-catalyzed C–H ethoxycarbonylation of 2-aryl-1,2,3-triazoles was developed by using diethyl azodicarboxylate as the esterification reagent. A wide variety of aryl esters containing 1,2,3-triazoles were obtained in moderate to good yields. In addition, density functional theory calculations were used to enhance the mechanistic studies.

Synthesis of isatins by the palladium-catalyzed intramolecular acylation of unactivated aryl C(sp2)–H bonds

Synthesis of isatins from formyl-N-arylformamides is achieved via PdCl2-catalyzed intramolecular acylation. This method shows the possibility of Pd-catalyzed aryl C(sp2)–H bond activation on the synthesis of isatins, affording an array of isatins in good yields. Yet this protocol is operationally simple and atom economical.

GLUT1-mediated venlafaxine-TDS-glucose conjugates with “lock-in” function for CNS delivery

Venlafaxine, a novel third‐generation antidepressant drug, has been described as a reference treatment for major depression, owing to its ability of inhibiting both noradrenalin and serotonin neuronal reuptake, and inhibiting dopamine reuptake slightly. However, its clinical application is hampered by a limited brain distribution. Glucosylation is an effective way to enhance the brain targeting ability of drugs, but the bidirectional transport of glucose transporter 1 (GLUT1) might decrease the concentrations of venlafaxine‐glucose (V‐G) in brain before the release of parent drug venlafaxine. To conquer this drawback of GLUT1, “lock‐in” thiamine disulfide system (TDS) was introduced to modify the V‐G conjugate. Both conjugates could release venlafaxine when incubated with the various buffers, mice plasma, and brain homogenate. The evaluation in vivo demonstrated that venlafaxine‐TDS‐glucose (V‐TDS‐G) had an improved targeting ability and significantly increased the level of venlafaxine in brain compared to the naked venlafaxine and V‐G. The relative uptake efficiency (RE) and concentration efficiency (CE) were enhanced to 5.69 and 5.70 times higher than that of naked venlafaxine, respectively. The results of this study suggest that the conjugate strategy based on the glucose‐TDS (G‐TDS) is available to enhance the delivery of central nervous system (CNS) drugs into brain.

Reactions of Disulfides with Silyl Phosphites to Generate Thiophosphates Under Neat Conditions

An efficient procedure for the synthesis of thiophosphates is described. Without using any metallic catalyst or base, the direct sulfur-phosphorus coupling reaction of disulfides and dialkyl trimethylsilyl phosphite (DTSP) was carried out under solvent-free reaction conditions in moderate to excellent yields with good functional group compatibility. The reaction conditions represent an advance over established methods not only in omitting the need for expensive catalysts or solvents, but also in shortening the reaction time significantly.These transformations are easy to conduct and can be readily applied to gram-scale preparation.

Visible light photoredox catalyzed thiophosphate synthesis using methylene blue as a promoter

A novel efficient method for the synthesis of thiophosphate derivatives catalyzed by methylene blue with blue light irradiation under an air atmosphere is described. The thiophosphate products, which are found in many pharmaceuticals and pesticides, were obtained in moderate to good yields. Moreover, Stern–Volmer fluorescence quenching experiments were conducted on reaction partners, demonstrating that the transformation involves photoinduced electron transfer. A plausible mechanism is proposed.

Total synthesis of the isoquinoline alkaloid decumbenine B via Ru(III)-catalyzed C–H activation

A novel and efficient method for the total synthesis of the natural product decumbenine B was described. The shortcomings in the existing synthetic routes of this isoquinoline alkaloid were minimized through the application of Ru(III)-catalyzed direct ortho-hydroxymethylation of intermediate 9. With this method, decumbenine B could be easily synthesized from commercially available materials by only five steps with an overall yield of 26.1%.

[Cp*RhIII]/Ionic Liquid as a Highly Efficient and Recyclable Catalytic Medium for C−H Amidation

A [Cp*RhIII ]-catalyzed direct C-H amidation is carried out in ionic liquid. Both C(sp2 )-H bonds of (hetero)arenes and alkenes and unactivated C(sp3 )-H bonds can be easily amidated with high functional-group tolerance and excellent yields under these conditions. Notably, using [Cp*RhIII ]/[BMIM]BF4 (BMIM=1-butyl-3-methylimidazolium) as the green and recyclable medium is environmentally benign, in light of characteristics such as the reusability of the expensive rhodium catalyst, avoidance of highly toxic organic solvents, and mild reaction conditions, as well as a short reaction time.