Hypervalent Iodine‐Mediated Synthesis of 1‐Aryl‐4‐methyl‐1,2,4‐triazolo[4,3‐a]quinoxalines by Oxidative Cyclization of Arene Carbaldehyde‐3‐methylquinoxalin‐2‐yl Hydrazones

Arene carbaldehyde‐3‐methylquinoxalin‐2‐yl hydrazones (2) obtained by the condensation of 2‐hydrazino‐3‐methylquinoxaline (1) with various aromatic aldehydes, on treatment with iodobenzene diacetate (IBD) in dichloromethane, undergo oxidative cyclization to exclusively afford 1‐aryl‐4‐methyl‐1,2,4‐triazolo[4,3‐a]quinoxalines (5) in excellent yield.     

Biofunctional organic nanocrystals for quantitative detection of pathogen deoxyribonucleic acid

Advances in nanotechnology have had significant impacts in the field of biodiagnostics. In this study, we describe the novel application of dissolvable, organic and biofunctional nanocrystals for the quantitative detection of a PCR product. Fluorescein diacetate (FDA), a fluorogenic precursor of fluorescein, was milled in a solution of a polymeric surfactant to create a stable, nanosized colloid with an interface for coupling streptavidin molecules. The application of these particulate labels for the quantitative detection of biotinylated human papillomavirus (HPV) DNA, amplified in a standard PCR procedure, was demonstrated. After the affinity reaction, the FDA molecules were dissolved and concomitantly converted into fluorescein. This approach resulted in a high selectivity, short incubation times and a sensitivity up to 147 times greater than obtained from state-of-the-art, directly fluorescent-labeled streptavidins. This innovative method offers rapid detection of small amounts of nucleic acids because less target material and thus fewer PCR cycles are required.     

[Hydroxy(tosyloxy)iodo]benzene-mediated regeneration of carbonyl compounds by cleavage of carbon nitrogen double bonds

[Hydroxy(tosyloxy)iodo]benzene (HTIB)-mediated regeneration of carbonyl compounds from various derivatives of carbonyl compounds of aryl and heteroaryl hydrazines containing adjacent nitrogen atoms is reported. These types of hydrazones cleaved oxidatively, giving back carbonyl compounds with HTIB, while cyclisation occurred with iodobenzene diacetate (IBD).     

Metal-free chemoselective oxidation of sulfides by in situ generated Koser’s reagent in aqueous media

Selective oxidation of sulfides was successfully performed by employing phenyliodine diacetate as an oxidant with the catalysis of TsOH in aqueous solution under mild conditions. Sulfoxides were formed with 1.1 equiv of PhI(OAc)₂ at room temperature; whereas sulfones were obtained in the presence of 2.1 equiv of PhI(OAc)₂ at 80 °C under otherwise identical conditions. Notably, various sulfides were converted to corresponding sulfoxides or sulfones in good to high yields by this metal-free protocol.     

An efficient and mild oxidant for the synthesis of s-tetrazines

PhI(OAc)₂ serves as a mild and effective oxidant for the synthesis of s-tetrazine derivatives—molecules of emerging significance to the field of bioorthogonal chemistry. This reagent serves as a complementary oxidant to harsher nitrous reagents. The use of PhI(OAc)₂ improves the synthesis of 5-amino-di(pyridin-2-yl)-s-tetrazine, a molecule that has been broadly used for cellular imaging and nuclear medicine. The generality of PhI(OAc)₂ as the oxidant for tetrazine synthesis is demonstrated for nine tetrazines in 75–98% yield.     

Copper(Ⅱ) and 2,2'-Biimidazole-promoted Novel Reaction of 4,4,4-Trifluoro-1-phenylbutane-1,3-diones with Iodobenzene Diacetate

A new and efficient way was developed to carry out the reaction of 4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dione with iodobenzene diacetate under the assistance of Cu(II) and 2,2′‐biimidazole at a low temperature in excellent yield. 2‐Acetoxyacetophenone was obtained unexpectedly.     

Polystyrene-Supported Iodobenzene Diacetate (PSIBD)–Mediated Synthesis of 1,2-Diacylbenzenes from 2-Hydroxyaryl Aldehyde/Ketone Acylhydrazones

Synthesis of some new 1,2-diacylbenzenes is described by the oxidation of 2-hydroxyaryl aldehyde/ketone acylhydrazones using polystyrene-supported iodobenzene diacetate (PSIBD) in good yield.     

二乙酸甘油酯封端的齐聚L-丙交酯增塑改性聚L-丙交酯薄膜

以二乙酸甘油酯(GD)引发L-丙交酯(LLA)开环聚合合成了二乙酸甘油酯封端的齐聚L-丙交酯(OGLA),并以此为增塑剂,以溶液共混法制备了OGLA与高分子量聚L-丙交酯(PLLA)的共混膜.采用DSC研究了共混膜的T_g和结晶性变化,考察了共混膜的力学性能和渗出性.结果表明:随着OGLA含量的增加,共混物T_g下降,结晶度降低,柔性提高;与聚乳酸相比,随着OGLA含量的增加,拉伸强度、弹性模量有一定程度降低,但断裂伸长率有较大程度的提高,力学性能得到较好的平衡;OGLA增塑体系与GD增塑体系相比较,优势在于避免了小分子增塑剂的渗出.     

SYNTHESES AND ACTIVE BEHAVIOR OF NOVEL UV PHOTOINITIATORS

A series of novel hybrid photoinitiators(YPhCOPhXPhI~+PhPF_6~-,Y = 4-NO_2,4-MeO or 3-Cl,X = O,OCH_2,or nothing),which contain multiple aromatic rings(PhCOPhXPh),were prepared by reaction of easily available aryl ketones (YPhCOPhXPh) with iodosobenzene diacetate[PhI~+OCOCH_3(CH_3CO_2)~-].The inset of an aromatic ring into p-benzoyldiphenyliodonium hexafluorophophate(PhCOPhI~+PhPF_6~-)(BDPIH,He-type photoinitiator) between diphenyliodonium and benzoyl is propitious both to the preparation and the photoinit...