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1.
A simple and highly efficient method for deprotection of allyl ethers has been developed using dimethylsulfoxide–sodium iodide (catalytic amount). This method is inexpensive, has simple reaction conditions, has an easy workup procedure, proceduces excellent yields (60–99%), and is effective for several structurally varied allyl ethers. 相似文献
2.
Highly selective deprotection of tert‐butyldimethylsilyl ethers at room temperature has been described using sulfated SnO2 as an efficient solid catalyst. 相似文献
3.
Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium. 相似文献
4.
A Convenient and Efficient Procedure for Oxime Ethers 总被引:1,自引:0,他引:1
Chun Bao LI* Yi CUI Wen Qin ZHANG Jian Lin LI Shuan Ming ZHANG Michael C. K. CHOI Albert S. C. CHAN Department of Chemistry Tianjin University Tianjin Open Laboratory of Chiraltechnology Department of Applied Biology and 《中国化学快报》2002,13(2)
In connection with our asymmetric reduction research, we are of interest to synthesize ketoxime ethers because they give good enantioselectivty in the reduction system of Lewis acid-NaBH4-Ligand1. In the literature the oxime ethers were made under anhydrous conditions using strong base such as NaH or sodium alkoxides to realize the substitution reaction between alkyl halide and oxime2. The reaction has also been performed under PTC conditions3. There were cases where the yields were low… 相似文献
5.
《合成通讯》2013,43(23):4043-4052
Abstract Catalytic amounts of bromodimethyl sulfonium bromide, or Nafion-H along with NaI (1 equiv.), in methanol cleave a variety of TBDMS ethers readily in high yields. Alkyl TBDMS ethers react more readily and selectively compared to phenolic TBDMS ethers, benzyl, and methyl ethers. 相似文献
6.
A General and Efficient Protocol for the Synthesis of Biaryl Ethers from Aryl Silyl Ethers Using Cs2CO3 总被引:1,自引:0,他引:1
Biary ethers are known to be important organic compounds for their biological interests and great presence in life science industries. A number of them have consequently provide a strong incentive for synthesis, which includes the classical Ullman reaction, metal-catalyzed substitution, SN-Ar based type, intramolecular oxidative coupling and MW-assisted methods. Although the above synthetic strategies are particularly important, a method is required for the direct conversion of phenoxy silane to biaryl ethers without recourse to hydrolytic conditions. 相似文献
7.
Dinesh S. Bhalerao 《合成通讯》2013,43(6):799-807
An efficient and convenient method for α-thiocyanation of ketones and β-dicarbonyl compounds has been developed using a reagent combination of bromodimethylsulfonium bromide (BDMS) and ammonium thiocyanate in acetonitrile. The developed method is mild and gave good yield of the products at room temperature. 相似文献
8.
Dr. Lijuan Feng Xuran Chen Meng Cao Shilei Zhao Dr. Hui Wang Dan Chen Dr. Yue Ma Prof. Tao Liu Prof. Ning Wang Prof. Yihui Yuan 《Angewandte Chemie (International ed. in English)》2023,62(45):e202312894
Nuclear accidents and the improper disposal of nuclear wastes have led to serious environmental radioactive pollutions. The rational design of adsorbents for the highly efficient separation of strontium(II) is essential in treating nuclear waste and recovering radioactive strontium resources. Metal–organic frameworks (MOFs) are potential materials for the separation of aqueous metal ions owing to their designable structure and tunable functionality. Herein, a novel 3D MOF material MOF-18Cr6, in which 1D channels are formed using 18-crown-6-ether-containing ligands as channel walls, is fabricated for strontium(II) separation. In contrast to traditional MOFs designed by grafting functional groups in the framework pores, MOF-18Cr6 possesses regular 18-crown-6-ether cavities on the channel walls, which not only can transport and intake strontium(II) via the channels, but also prevent blockage of the channels after the binding of strontium(II). Consequently, the functional sites are fully utilized to achieve a high strontium(II) removal rate of 99.73 % in simulated nuclear wastewater. This study fabricates a highly promising adsorbent for the separation of aqueous radioactive strontium(II), and more importantly, can provide a new strategy for the rational design of high-performance MOF adsorbents for separating target substances from complex aqueous environments. 相似文献
9.
Claudio A. Jiménez 《合成通讯》2013,43(14):2391-2397
A simple and efficient procedure to synthesize highly hindered alkyl aryl ketones that involves the coupling of N,N‐dimethyl‐3,5‐di‐tert‐butylsalicylamide with organolithium compounds is described. Mild reaction conditions and good to excellent yields of the products are the noteworthy advantages of the procedure. 相似文献
10.
《合成通讯》2013,43(22):3891-3896
Abstract Simultaneous de-O-xylylation and reductive coupling was observed when 1 equiv. of the dialdehyde 2a/2b was treated with 5 equiv. of each TiCl4 and Zinc which lead to the development of TiCl4 in dioxane as a new system for the facile deprotection of phenolic ethers 4a–4d, 5a–5d, and 6a–6c. 相似文献
11.
12.
Wong Ken-Tsung 《合成化学》2004,(Z1)
Advances made in the molecular design of modern optoelectronic materials have made significant contributions toward the development of organic electronics. The organic light-emitting devices (OLEDs) employing monodisperse or polymeric conjugated materials possess the most promising prospects. However, materials suitable for long-term use as blue light emitters are still far from optimization in terms of stability. In the past few years, interesting materials based on 9,9-diaryl-substituted f… 相似文献
13.
Davir González-Calderón Luis J. Benitez-Puebla Carlos A. Gonzalez-Gonzalez Marco A. Garcia-Eleno Aydeé Fuentes-Benitez Erick Cuevas-Yañez 《合成通讯》2014,44(9):1258-1265
tert-Butyldimethylsilyl (TBS) phenyl / alkyl ethers were cleaved to the corresponding efficiently parent hydroxyl compounds in good yields using catalytic amounts of AlCl3 · 6H2O by conventional or microwave-assisted heating in methanol or isopropanol solution. Intramolecular and competitive experiments demonstrated the chemoselective deprotection of TBS ethers in the presence of triisopropylsilyl and tert-butyldiphenylsilyl ethers. 相似文献
14.
A tetrameric DABCO–bromine complex was synthesized, characterized, and utilized as a novel active bromine complex for the oxidative deprotection of THP and silyl ethers and semicarbazones to carbonyl compounds. 相似文献
15.
BF3·OEt2 (Boron trifluoride etherate), an inexpensive and commercially easily available Lewis acid stoichiometrically employed for Beckamann rearrangement in general, was now found to efficiently catalyze Beckmann rearrangement of ketoximes into their corresponding amides (up to 99% yield) in anhydrous acetonitrile under reflux temperature. 相似文献
16.
Flavansrefertoalargegroupofnaturallyoccurringcompoundspossessinga2-phenyl-chromannucleus.Naturallyoccurringflavansexhibitanumberofimportantbiologicalactivitieswhichifexploitedproperly,mayleadtovaluablenewdrugsoragrochemicals'.Inflavansynthesis,thekeystepistoconstructthe3,4-dihydrobenzopyranring-Variousmethodshavebeendevelopedfortheringformation,butmostoftheminvolvemultiplestepsandgivelowoverallyields2.Inthispaper,BF3wasusedforthefirsttimeasanefficientcatalysttoformthepyranringfroml,3-diaryIp… 相似文献
17.
Multi-dentateligandssuchasopen-chainandcycliccrownethershavereceivedextensiveintCrestsandbeenmuchstudiedinhost-guestinteraction,supramolecularandbioorganicchemistry".Asabindingand/orcatalyticsiteintheactivecenterofmetalloenzymesandnon-metalloenzymes,imidazoleplaysaveryimportantroleinbiologicalsystem.Imidazole-basedbiomimeticmodelsandmacrocycles,especiallyrecentimidazoliumcyclophaneshavebeenpaidincreasingattention5-ll.Inspiteofthis,onlyoneliteratUre,toourknowledge,reportedthesynthesisofbis(N-i… 相似文献
18.
Summary. A synthetic utility of 3-carboxypyridinium (CPCC) and 2,2-bipyridinium (BPCC) chlorochromates in deprotection reactions is reported. Different types of thioamides, thioureas, thiono esters, and thioketones are deprotected to their corresponding carbonyl compounds with these reagents in good to excellent yields. The reactions were carried out in solution, under solvent-free conditions, and under microwave irradiation. The results show that with both reagents the rates of the reactions and the yields are usually highest under microwave irradiation. 相似文献
19.
JunHUA ZhiYongJIANG YanGuangWANG 《中国化学快报》2004,15(12):1430-1432
An efficient and selective method for the deprotection of primary alcoholic tert-butyl-dimethylsilyl (TBS) ethers using SnC12“2H20 as catalyst is described. The reaction conditions allow primary alcoholic TBS ethers to be desilylated chemoselectively in the presence of phenolic TBS ethers, secondary and tertiary alcolholic TBS ethers, and the extensively used TBDPS-, acetyl-, benzyloxycarbonyl-, p-toluenesulfonyl- and benzyl protective groups. 相似文献
20.
An efficient and generally applicable method for stepwise α-alkylatton of esters, nitriles, and ketones via the α-tert-butylthio derivatives is described. The method involves reductive-protonation and reductive-alkylation of α-alkylthio α,α-bis-alkylated carbonyl compounds which are prepared by stepwise alkylation of the corresponding simple α-alkylthio carbonyl precursors. The reduction is conveniently performed by use of stoichiometric amounts of a dissolving metal, particularly lithium, affording correspondingly the α-mono-and the α,α-bis-alkylated carbonyl compounds in good yields. 相似文献