45037-67-0Relevant articles and documents
Synthesis and properties of gemini-type hydrocarbon-fluorocarbon hybrid surfactants
Ohno, Aimi,Kushiyama, Atsunori,Kondo, Yukishige,Teranaka, Toshio,Yoshino, Norio
, p. 577 - 582 (2008)
Gemini-type hybrid surfactants with two fluorocarbon chains connected through a hydrocarbon spacer, F(CF2)m(CH2)2CH(OSO3Na)(CH2)nCH(OSO3Na)(CH2)2(CF2)mF [Fm(Hn)FmOS, m = 4, 6; n = 5, 6, 7, 8)], were synthesized and their surface chemical properties were examined with the aim to have highly functional and highly water-soluble fluorinated surfactants when compared with the conventional fluorinated surfactants. Comparisons of the surface chemical properties of the synthesized gemini-type hybrid surfactants with those of monounit-type hybrid surfactants, F(CF2)m(CH2)2CH(OSO3Na)(CH2)nH [FmEHnOS, m = 4, 6; n = 3, 5)], revealed that gemination causes a remarkable lowering (about 1/100) in cmc value while it produces little changes in Krafft point (below 0 °C) and surface tension at cmc (γcmc).
Selective TEMPO-Oxidation of Alcohols to Aldehydes in Alternative Organic Solvents
Hinzmann, Alessa,Stricker, Michael,Busch, Jasmin,Glinski, Sylvia,Oike, Keiko,Gr?ger, Harald
, p. 2399 - 2408 (2020/04/29)
The TEMPO-catalyzed oxidation of alcohols to aldehydes has emerged to one of the most widely applied methodologies for such transformations. Advantages are the utilization of sodium hypochlorite, a component of household bleach, as an oxidation agent and the use of water as a co-solvent. However, a major drawback of this method is the often occurring strict limitation to use dichloromethane as an organic solvent in a biphasic reaction medium with water. Previous studies show that dichloromethane cannot easily be substituted because a decrease of selectivity or inhibition of the reaction is observed by using alternative organic solvents. Thus, up to now, only a few examples are known in which after a tedious optimization of the reaction dichloromethane could be replaced. In order to overcome the current limitations, we were interested in finding a TEMPO-oxidation method in alternative organic solvents, which is applicable for various alcohol oxidations. As a result, we found a method for N-oxyl radical-catalyzed oxidation using sodium hypochlorite as an oxidation agent in nitriles as an organic solvent component instead of dichloromethane. Besides the oxidation of aromatic primary alcohols also aliphatic primary alcohols, secondary alcohols as well as dialcohols were successfully converted when using this method, showing high selectivity towards the carbonyl compound and low amounts of the acid side-product.
Highly Discriminative and Chemoselective Deprotection/Transformations of Acetals with the Combination of Trialkylsilyl Triflate/2,4,6-Collidine
Ohta, Reiya,Matsumoto, Nao,Ueyama, Yoshifumi,Kuboki, Yuichi,Aoyama, Hiroshi,Murai, Kenichi,Arisawa, Mitsuhiro,Maegawa, Tomohiro,Fujioka, Hiromichi
, p. 6432 - 6443 (2018/05/30)
Acetals are the most useful protecting groups for carbonyl functional groups. In addition to the role of protection, they can also be used as synthons of carbonyl functions. Previously, we developed a chemoselective deprotection and nucleophilic substitution of acetals from aldehydes in the presence of ketals. This article describes the highly discriminative and chemoselective transformations of acetals bearing different substitution patterns, different types of acetals, as well as mixed acetals. These reactions can achieve the transformations that cannot be attained by conventional methods, and their results strongly suggest the combination of R3SiOTf/2,4,6-collidine to promote such unprecedented phenomena.
Oxidation of terminal diols using an oxoammonium salt: A systematic study
Miller, Shelli A.,Bobbitt, James M.,Leadbeater, Nicholas E.
supporting information, p. 2817 - 2822 (2017/04/04)
A systematic study of the oxidation of a range of terminal diols is reported, employing the oxoammonium salt 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (4-NHAc-TEMPO+ BF4-) as the oxidant. For substrates bearing a hydrocarbon chain of seven carbon atoms or more, the sole product is the dialdehyde. A series of post-oxidation reactions have been performed showing that the product mixture resulting from the oxidation step can be taken on directly to a subsequent transformation. For diols containing four to six carbon atoms, the lactone product is the major product upon oxidation. In the case of 1,2-ethanediol and 1,3-propanediol, when using a 1 : 0.5 stoichiometric ratio of substrate to oxidant, the corresponding monoaldehyde is formed which reacts rapidly with further diol to yield the acetal product. This is of particular synthetic value given both the difficulty of their preparation using other approaches and also their potential application in further reaction chemistry.