Concise synthesis and characterization of novel seco-steroids bearing a spiro-oxetane instead of a metabolically labile C3-hydroxy group

Two novel stereoisomeric analogues of 1,25-dihydroxyvitamin D₃ bearing a spiro-oxetane at the C3 position of the A-ring have been designed and synthesized in a convergent manner. The absolute configuration at the C1 position of the synthesized compounds was determined by the circular dichroism exciton chirality method using the corresponding C1-allylic benzoates. The replacement of the C3-hydroxy group with a spiro-oxetane provided an advantageous conformational preference for the parent seco-steroids, which would facilitate the formation of a stable receptor complex.     

Application of oxetane ring opening toward stereoselective synthesis of zincophorin fragment

A stereoselective synthesis of the C1–C11 fragment of zincophorin was achieved by using an intramolecular oxetane ring opening reaction as the key step. The oxetane moiety was synthesized by employing a desymmetrization protocol developed at our group and a non-Evans syn aldol as the key steps toward the synthesis.     

A Direct Synthesis of Highly Substituted π‐Rich Aromatic Heterocycles from Oxetanes

The ubiquitous use of π‐rich five‐membered heterocycles has driven the development of new methods for their synthesis for more than a century. Here, we disclose a general and reliable reaction manifold for the construction of highly substituted heterocycles through a facile Lewis‐acid‐catalyzed oxetane rearrangement. Notably, this methodology employs a keto‐oxetane motif as a 1,4‐dicarbonyl surrogate, which can be synthesized using robust alkylation or alkenylation reactions, and thus obviates the need to access 1,4‐dicarbonyl compounds via umpoled starting materials. We harnessed this reactivity to generate a broad range of substituted furans and pyrroles, and extended this methodology to produce benzo‐fused versions thereof.     

Synthesis and cationic photocuring of new carbazole monomers

New carbazole monomers were synthesized and their cationic photopolymerization investigated. The monomers contain in each molecule two pendant carbazole groups and two functional groups reactive towards cationic photopolymerization. The investigated reactive groups were epoxy, oxetane or vinyl ether. Each type of monomer contains a spacer group namely ethylene oxide segment. The UV curing kinetics of the different monomers was monitored by real time FT-IR (RT-FTIR) analysis and the thermal properties evaluated by DSC.     

Synthesis of Perfluorinated Oxetane and Surface Properties of Its Cationic UV Cured Coating as a Reactive Additive

Perfluorinated oxetane(F-OXE) was synthesized via the ring-opening reaction of epoxy-functionalized oxetane with 2-(perfluorooctyl)ethanol under base-catalysis, and characterized by FTIR and ¹H NMR spectroscopy. The synthesized F-OXE was mixed with a commercial cationic UV curable resin, UVR6110, as a reactive additive at different mass fractions, and UV-irradiation cured in the presence of triphenylsulphonium hexafluoroantimonate as a cationic photoinitiator. The surface property study of cured films indicated that both hydrophobicity and oleophobicity were effectively enhanced by the addition of a small amount of F-OXE. The contact angles of water and 1-bromonaphthalene on the surface of the cured film with 1.0%(mass fraction) F-OXE loading increased from 72° to 106° and from 0° to 76°, respectively, compared with those on the surface of the film without F-OXE addition. The surface tension of UVR6110-F-OXE cured film decreased greatly from 55.6 mN/m of referenced film to 22.9 mN/m. The results from X-ray photoelectron spectroscopy analysis confirm the migration and aggregation effect of perfluoroalkyl group to the surface of cured film. For 1%(mass fraction) addition of F-OXE, the relative content of fluorine greatly increased from 0.70%(mass fraction) in the interior of the cured film to 36.73%(mass fraction) at the surface of the cured film, whereas those of carbon and oxygen decreased from 73.29% to 40.96% and from 26.00% to 22.30%, respectively.     

Electrophilic Azido Selenenylation of Alkenes. A Simple Synthetic Route to Racemic Taxol Side Chain

Simple alkenes react with PhSeOTf and NaN₃ in MeCN to afford β-phenylseleno azides as the result of a stereospecific trans addition. The regioselectivity of the process is determined by the structure of the alkene.     

一种可光交联聚芴蓝光材料的合成与表征

有机电致发光器件代表了未来显示技术的发展趋势,已引起学术界、企业界和政府部门的广泛关注[1~4].目前,全色显示是有机电致发光器件商业化的控制因素之一,成为当前研究的一项热点.利用多层器件结构获得的白色电致发光器件,可以有效地提高平板显示器的分辨率.与有机小分子相比,     

梳形聚醚全固态聚合物电解质的电导率研究

应用阳离子开环聚合反应合成含二缩三乙二醇单甲醚侧链的梳形聚醚POE,并与高氯酸锂复配制成聚合物电解质.交流阻抗测试表明,当POE电解质内的氧锂比(O/L i)为20时,其电导率最高,室温下为10-4.43S/cm,80℃时则达到10-3.44S/cm.用DSC和XPS分别表征了链段运动能力和锂盐在POE中的溶解状态对电导率的影响.