10.1002/chem.202101459
The research focuses on the regioselective synthesis of 4-aryl-1,3-dihydroxy-2-naphthoates, which feature a less accessible 1,2,3,4-tetrasubstituted naphthalene scaffold and exhibit photoluminescence properties. The synthesis is achieved through a 1,2-aryl-migrative ring rearrangement reaction involving brominated lactol silyl ethers. The study explores the reactivity of C4-halogenated lactol silyl ethers, such as 5a-X (X = Cl, Br, I), and optimizes the reaction conditions using various substrates to obtain the desired 4-aryl-1,3-dihydroxy-2-naphthoates 6 in high yields. The experiments involve the use of reagents like TBAF, NaOAc, and AcOH, and analytical techniques such as TLC, 1H NMR, and single-crystal X-ray diffraction are employed to monitor the reaction progress and confirm the structures of the products. The synthesized compounds are characterized by their photophysical properties, including UV-Vis absorption and photoluminescence (PLE) spectra, which are influenced by the electronic nature of the aryl groups and the intramolecular hydrogen bonding within the molecules.
10.1016/S0008-6215(00)80792-2
The research aimed to investigate the selective protection of hydroxyl groups in sucrose using tert-butyldiphenylsilyl chloride (t-BDPS) as a reagent. The purpose was to explore the preferential blocking of primary hydroxyl groups in sugar derivatives, recognizing the value of t-BDPS for this purpose due to its stability towards acid and hydrogenolysis compared to related silyl and trityl ethers. The study focused on the synthesis and reactions of 6’-mono-, 6,6’-di-, and 6,1’,6’-tri-t-BDPS ethers of sucrose. The researchers found that the reaction of sucrose with t-BDPS chloride in pyridine, in the presence of 4-dimethylaminopyridine, yielded the crystalline 6’-t-BDPS ether without the need for column chromatography. Further reactions led to the formation of 4,6,1’-trichloride and other derivatives, with the 6,1’,6’-tri-t-BDPS ether being the major product when using 4.6 mol. equiv. of the silylating reagent. The study concluded that the t-BDPS group is an important synthetic intermediate in carbohydrate chemistry due to its stability and the preferential removal of other protecting groups in its presence. Key chemicals used in the process included t-BDPS chloride, pyridine, 4-dimethylaminopyridine, sulphuryl chloride, tetrabutylammonium fluoride, acetic anhydride, and benzoyl chloride.
10.1021/jo00304a024
The research focuses on the stereocontrolled total syntheses of penicillanic acid S,S-dioxide (10) and 6-aminopenicillanic acid (26) derived from (S)-aspartic acid and (R,R)-tartaric acid, respectively. The study's key steps involve the preparation and cyclization of nitroalkenes 8 and 23, with the reaction of these compounds with tetrabutylammonium fluoride followed by ozone and DBU yielding the bicyclic P-lactams 9 and 24, which are then transformed into the target penicillanic acid derivatives 10 and 26. The research concludes that (benzyloxy)nitromethane is a highly useful reagent in β-lactam chemistry, and the nitroalkene ring closure strategy is efficient and effective for preparing polyfunctional bicyclic β-lactams, with potential general applicability for constructing novel β-lactam systems.
10.1021/ja000530v
The research aimed to explore and characterize the first examples of ammonium selenothioates, which are selenium analogs of dithioic acids and their salts. Despite being largely unexplored, these compounds are fundamentally important for understanding the electronic properties of heavy atom-containing conjugate ions and for synthesizing various selenothioates. The researchers synthesized ammonium selenothioates using selenothioic acid S-2-trimethylsilylethyl esters as precursors, reacting them with tetrabutylammonium fluoride in THF. The resulting ammonium selenothioates were characterized using NMR spectroscopy and X-ray crystallography, revealing their electronic properties and structural features.
10.1039/c3dt32983f
This study aims to investigate the mechanism of hydrosilylation of styryl alcohols initiated by N-heterocyclic carbenes (NHC) in the presence of dihydrosilane. Tetrabutylammonium fluoride (TBAF) is used to quench the reaction, terminating the hydrosilylation process by reacting with any remaining silicon derivatives. It is a quaternary ammonium salt with four n-butyl groups attached to a nitrogen atom and a fluoride ion. TBAF is an effective scavenger of silicon-containing species and is commonly used in organic synthesis to terminate reactions involving silicon reagents. Sodium hydride (NaH) has been tested as an alternative base to NHC to initiate hydrosilylation reactions. It is known for its strong basicity and ability to deprotonate alcohols. It consists of a sodium cation and a hydride ion. NaH can generate alkoxides by deprotonating alcohols, which can then react with dihydrosilane to form high-valent silicon complexes.
10.1016/j.tetlet.2010.09.007
The research focuses on the development of a simple and robust method for the preparation of 11C-labeled ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), using Tetrabutylammonium fluoride (TBAF)-promoted α-[11C]methylation of α-arylesters. This method is suitable for remote-controlled synthesis and is advantageous for positron emission tomography (PET) tracer development. The experiments involved the use of TBAF as a base to activate the α-carbon of various α-arylesters, including methyl phenylacetate and its derivatives, under homogeneous conditions. The reactants included the 11C-labeling agent iodo[11C]methane (1), different α-arylesters (2a-e), and TBAF. The analyses used to assess the radiochemical conversion and purity of the products included radiochromatography with analytical high-performance liquid chromatography (HPLC). The study also investigated the influence of electron-withdrawing and donating groups on the [11C]methylation efficiency and confirmed the active base for the reaction to be fluoride, even in a hydrated form. The method was optimized for the synthesis of 11C-labeled ibuprofen, which involved the hydrolysis of the ester 3d to yield the acid form 5, and was amenable to remote-controlled synthesis, demonstrating its potential for PET tracer development.
10.1039/c2jm32489j
The research primarily focuses on the synthesis and evaluation of a high-birefringence polymethacrylate with a diphenyl-diacetylene (DPDA) moiety in the side chain. The polymer was designed to form a nematic liquid crystal (LC) phase with a wide temperature range and exhibit high birefringence, which is crucial for applications in optical devices such as flat panel displays, optical fibers, and photostorage devices. The synthesis involved Negishi cross-coupling of an asymmetric diacetylene protected with a tert-butyldimethylsilyl (TBDMS) group and 2,2-dibromoalkene, followed by E2 reaction and deprotection with tetra-n-butylammonium fluoride (TBAF), and esterification with methacrylate chloride. Anion polymerization using n-butyllithium (n-BuLi) was employed to obtain the final polymer. The thermal properties were analyzed using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM), while the optical properties, specifically the birefringence, were determined through UV-visible spectroscopy and a microscope spectroscopic method with a Nikon LV100 Pol optical microscope and a USB4000 spectrometer. The polymer showed a high birefringence of 0.3 at 550 nm at room temperature, indicating its potential for use in optical applications.
10.1016/S0040-4039(97)00701-6
The research focuses on the enantioselective acyclic stereoselection under catalyst control, specifically the asymmetric synthesis of syn- and anti-1,3-diols incorporating an acetate equivalent. The purpose of this study was to develop a method for the enantioselective synthesis of 1,3-diols, which are fundamental units found in polyene macrolide antibiotics and other compounds, through the chiral oxazaborolidinone-catalyzed aldol reaction. The researchers concluded that by choosing the appropriate stereochemistry of the catalyst, they could achieve complete stereoselection in the production of these 1,3-diols, demonstrating that the stereochemistry of the substrates did not affect the reaction outcome. Key chemicals used in the process include chiral oxazaborolidinones, silyl ketene acetal, dithiolane moiety, and various aldehydes, along with reagents like nickel boride and chiral boranes for the aldol reaction, and tetrabutylammonium fluoride for deprotection steps.
10.1016/j.tetlet.2011.07.032
The research focuses on the development of a common and stereoselective strategy for the synthesis of N,O,O,O-tetra-acetyl D-ribo-(2S,3S,4R)-phytosphingosine and 2-epi-jaspine B, two biologically significant compounds. The purpose of this study was to create an efficient method for synthesizing these compounds due to their importance in cell regulation, signal transduction, and antitumor, antiviral, and antifungal activities. The researchers achieved this by employing Grignard addition on N-benzyl sugar lactamine and Wittig olefination as key steps. Starting from D-ribose, an inexpensive sugar with the desired chirality, the synthesis involved a series of chemical reactions including the use of benzylamine, vinylmagnesium bromide, CbzCl (carbazole-9-yl chloride), ozone, NaBH4 (sodium borohydride), sodium hydride, tetra-n-butylammonium fluoride (TBAF), NaIO4 (sodium periodate), and various other reagents to protect and deprotect functional groups, as well as to introduce the necessary lipid chain and amino group. The successful synthesis of the target compounds was confirmed by comparing their physical properties with reported values, thus demonstrating a general strategy for the synthesis of these important sphingolipids and their derivatives.
10.1007/s10847-010-9813-5
The study presents the development of a new colorimetric anion sensor 1, synthesized using Fat Brown RR dye and a nitrophenyl group as signaling components, and an amide moiety as the binding site. The receptor 1 is designed to selectively recognize fluoride and acetate ions through color changes observable both via spectroscopic methods and to the naked eye. The receptor was synthesized by reacting Fat Brown RR with 4-nitrobenzoyl chloride, yielding a red solid in 76.3% yield. In DMSO, the receptor displayed strong absorption at 412 nm, which shifted upon addition of tetrabutylammonium fluoride, indicating complex formation. Excess fluoride ions led to deprotonation, evidenced by a new absorption band at 531 nm. Similar behavior was observed with acetate ions. The receptor did not bind to other anions like chloride, bromide, iodide, perchlorate, hydrogensulfate, or nitrate. The association constants for fluoride and acetate were determined through UV–vis and 1H NMR titrations, confirming the receptor's selectivity and efficiency as a naked-eye detector for these anions.
Xi, 
F, 
C
