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91.
Mehdi Javaheri M. Reza Naimi-Jamal Mohammad G. Dekamin Gerd Kaupp 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):142-148
Abstract In this study, trialkylsilyl ethers of indispensable protected alcohols are oxidatively deprotected in neat form with gaseous nitrogen dioxide (NO2). Quantitative yields of aldehydes or ketones are obtained without the necessity of chromatography. The byproducts, nitrogen monoxide, anhydrous nitric acid, and hexamethyldisiloxane, can be quantitatively separated by evaporation and distillation in closed systems for recycling or further use. The direct new method supersedes the previous techniques that produce dangerous wastes and require chromatographic workup, while the atmospheric gas NO2 and its gaseous reduction products are easily kept in closed systems until further use. 相似文献
92.
Ramin Ghorbani-Vaghei Ardeshir Khazaei 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1169-1173
N-Bromobis(p-toluenesulfonyl)amine (NBBTA) is a novel and efficient reagent for the conversion of oximes to their corresponding carbonyl compounds in good yields under mild conditions. 相似文献
93.
《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2621-2625
Deprotection of phenylhydrazones, paranitrophenylhydrazones, and semicarbazones to their parent aldehydes and ketones in high yields has been carried out using benzyltriphenylphosphonium peroxodisulfate as a selective oxidant under mild conditions. 相似文献
94.
1,3‐Oxathiolanes are smoothly deprotected to carbonyl compounds by IBX at room temperature with β‐cyclodextrin as a catalyst and water as solvent. 相似文献
95.
Regeneration of Carbonyl compounds from the corresponding thioketals in nitrogen heterocycles have been effected using Dowex 50W acidic catalyst in reasonable yields. 相似文献
96.
Joseph AlmogShmuel Cohen 《Tetrahedron letters》2003,44(16):3285-3288
1,2-Indanedione reacts with two equivalents of 2-mercaptoethanol to produce, instead of the expected 1,2-bis(1,3-oxathiolane), a dioxa-dithia[4.4.3] propellane. Other 1,2-indanediones produce analogous compounds. The protecting groups are removed at room temperature with NBS in aqueous acetone, to produce the original diketone. 相似文献
97.
Hiroshi Ito 《Journal of polymer science. Part A, Polymer chemistry》2003,41(24):3863-3870
The chemical amplification concept aimed at dramatically boosting the resist sensitivity was invented at IBM Research in San Jose, CA, in 1980. The sensitivity enhancement is achieved by generating acid by irradiation, which induces a cascade of chemical transformations in a resist film. A chemically amplified resist based on acid‐catalyzed deprotection was quickly employed in the mid‐80s in manufacture of 1 megabit (Mbit) dynamic random access memory (DRAM) devices by deep ultraviolet (UV) (~250 nm) lithography in IBM. The unexpectedly high‐resolution capability of chemical amplification resists promoted their acceptance in the resist community and the microelectronics industry. All the advanced lithographic technologies (current workhorse 248 nm, maturing 193 nm, and emerging 157 nm, extreme UV, and projection electron beam) depend on chemical amplification resists. This article describes the invention, implementation in device manufacturing, current status, and future perspective of chemical amplification resists. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3863–3870, 2003 相似文献
98.
An efficient and chemoselective deprotection of prenyl ethers of phenols and alcohols with ZrCl4/NaBH4 in DCM was achieved in high yields. The selectivity of prenyl ether deprotection is well demonstrated by carrying out the reaction in the presence of several other ether and ester functionalities. 相似文献
99.
碘/甲醇体系对甘油醚脱保护 总被引:3,自引:0,他引:3
1-烷氧基-2乙酰氧基-3-三苯甲氧基甘油醚与碘/甲醇体系反应,在60 ℃时, 同时发生了脱三苯甲基及乙酰基,在室温下,仅脱三苯甲基,但乙酰基在反应过程 中发生了部分转移,产生了两个异构体。碘/甲醇体系与1-烷氧基-2,3-异丙叉甘 油醚反应,高收率地生成1-烷氧基甘油。脱保护机理是一个酸催化过程,据此提出 并证实了碘水四氧呋喃体系同样能进行上述脱保护反应。 相似文献
100.
S. Malla Reddy 《Tetrahedron letters》2005,46(43):7439-7441
Acetonides are hydrolyzed selectively and efficiently with lanthanum(III) nitrate hexahydrate in acetonitrile. The method has good compatibility with other sensitive hydroxyl protecting groups such as trityl, TBDMS, THP, OAc, OBz and OBn. 相似文献