Introduction This study forms part of a 2-year longitudinal clinical trial to compare the performance of a gallium-based restorative material (Galloy) with a high copper, mercury based (Dispersalloy) control material.Method Following Ethical Committee approval, 25 galley restorations and 25 Dispersalloy controls were placed in 14 adult patients, by a single operator. The cavities were of moderate size, indicating the use of amalgam as the restorative material. All restorations were polished within 1 week of placement, photographed and a silicone impression of the tooth and restoration recorded. In addition, a visual analogue scale (VAS), indicating the extent of any post-operative sensitivity, was completed by each patient for each restoration, immediately prior to polishing. A score of 0 indicated no sensitivity, while a score of 10 indicated the greatest possible sensitivity. At B-month recall, the VAS scores, silicone impressions and photographs were repeated.Results The mean sensitivity scores for the galley and Dispersalloy restorations at 1 week were 5.1 (+/-3.4) and 1.0 (+/-1.5), respectively and at 6 months, 1.8 (+/-3.0) and 0.2 (+/-0.1) respectively. The differences between these means at 1 week and at 6 months were significant (P < 0.01).Conclusion Galley restorations were associated with a much greater severity of post-operative sensitivity than Dispersalloy restorations.
Triphenylphosphine-Catalyzed Dehydrogenative Coupling Reaction of Carboxylic Acids with Silanes – A Convenient Method for the Preparation of Silyl Esters
作者:Guo-Bin Liu、Hong-Yun Zhao、Thies Thiemann
DOI:10.1002/adsc.200600338
日期:2007.4.2
Triphenylphosphine has been found to be an efficient catalyst for the dehydrosilylation of carboxylic acids with silanes. In the presence of 4 mol % of triphenylphosphine (PPh3), dehydrosilylation reactions in DMF afforded the corresponding silyl esters at 120 °C in good yield.
Alcohols, phenols and carboxylic acids are silylated with very good yields in the presence of silyl methallylsulfinates under non-basic conditions and with the formation of volatile co-products.
Preparation of Silyl Esters by ZnCl<sub>2</sub>-Catalyzed Dehydrogenative Cross-Coupling of Carboxylic Acids and Silanes
作者:Guo-Bin Liu
DOI:10.1055/s-2006-941576
日期:2006.6
An efficient route to silyl esters by dehydrogenative cross-coupling of silanes and carboxylic acids was investigated. Treatment of silanes and carboxylic acids in the presence of 15mol% of ZnCl2 in DMF at 120 °C afforded the corresponding silyl esters in good yields under relatively mild conditions.
Nickel-Catalyzed Hydrosilylation of CO<sub>2</sub> in the Presence of Et<sub>3</sub>B for the Synthesis of Formic Acid and Related Formates
作者:Lucero González-Sebastián、Marcos Flores-Alamo、Juventino J. Garcı́a
DOI:10.1021/om400876j
日期:2013.12.9
The reaction of CO2 with Et3SiH catalyzed by the nickel complex [(dippe)Ni(μ-H)]2 (1) afforded the reduction products Et3SiOCH2OSiEt3 (12%), Et3SiOCH3 (3%), and CO, which were characterized by standard spectroscopic methods. Part of the generated CO was found as the complex [(dippe)Ni(CO)]2 (2), which was characterized by single-crystal X-ray diffraction. When the same reaction was carried out in the
A series of in situ‐prepared catalytic systems incorporating RuII precursors and bidentatephosphineligands has been probed in the reductive carboxylation of ethylene in the presence of triethylsilane as reductant. The catalytic production of propionate and acrylate silyl esters was evidenced by high‐throughput screening (HTS) and implemented in batch reactor techniques. The most promising catalyst