1663-61-2Relevant articles and documents
Synthesis method of crude carboxylic ester (by machine translation)
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Paragraph 0021-0023, (2020/08/09)
The method is characterized in that the carboxylic ester and the ether are prepared by reacting a carboxylic ester with an ether at a certain temperature under the catalysis of a catalyst at a certain pressure for a certain time. (by machine translation)
Anodic oxidation of dithiane carboxylic acids: A rapid and mild way to access functionalized orthoesters
Denis, Camille,Dobbs, Adrian P.,Garcia, Anthony D.,Goodall, Iain C. A.,Lam, Kevin,Leech, Matthew C.,Petti, Alessia
, p. 4000 - 4005 (2020/06/08)
A new electrochemical methodology has been developed for the preparation of a wide variety of functionalized orthoesters under mild and green conditions from easily accessible dithiane derivatives. The new methodology also offers an unprecedented way to access tri(fluorinated) orthoesters, a class of compound that has never been studied before. This provides the community with a rapid and general method to prepare libraries of functionalized orthoesters from simple and readily available starting materials.
Self-assembled orthoester cryptands: Orthoester scope, post-functionalization, kinetic locking and tunable degradation kinetics
L?w, Henrik,Mena-Osteritz, Elena,Von Delius, Max
, p. 4785 - 4793 (2018/06/07)
Dynamic adaptability and biodegradability are key features of functional, 21st century host-guest systems. We have recently discovered a class of tripodal supramolecular hosts, in which two orthoesters act as constitutionally dynamic bridgeheads. Having previously demonstrated the adaptive nature of these hosts, we now report the synthesis and characterization-including eight solid state structures-of a diverse set of orthoester cages, which provides evidence for the broad scope of this new host class. With the same set of compounds, we demonstrated that the rates of orthoester exchange and hydrolysis can be tuned over a remarkably wide range, from rapid hydrolysis at pH 8 to nearly inert at pH 1, and that the Taft parameter of the orthoester substituent allows an adequate prediction of the reaction kinetics. Moreover, the synthesis of an alkyne-capped cryptand enabled the post-functionalization of orthoester cryptands by Sonogashira and CuAAC "click" reactions. The methylation of the resulting triazole furnished a cryptate that was kinetically inert towards orthoester exchange and hydrolysis at pH > 1, which is equivalent to the "turnoff" of constitutionally dynamic imines by means of reduction. These findings indicate that orthoester cages may be more broadly useful than anticipated, e.g. as drug delivery agents with precisely tunable biodegradability or, thanks to the kinetic locking strategy, as ion sensors.
Orthoester exchange: A tripodal tool for dynamic covalent and systems chemistry
Brachvogel, Ren-Chris,Von Delius, Max
, p. 1399 - 1403 (2015/02/05)
Reversible covalent reactions have become an important tool in supramolecular chemistry and materials science. Here we introduce the acid-catalyzed exchange of O,O,O-orthoesters to the toolbox of dynamic covalent chemistry. We demonstrate that orthoesters readily exchange with a wide range of alcohols under mild conditions and we disclose the first report of an orthoester metathesis reaction. We also show that dynamic orthoester systems give rise to pronounced metal template effects, which can best be understood by agonistic relationships in a three-dimensional network analysis. Due to the tripodal architecture of orthoesters, the exchange process described herein could find unique applications in dynamic polymers, porous materials and host-guest architectures.
Aromatic Nitration under Neutral Conditions Using Nitrogen Dioxide and Ozone as the Nitrating Agent. Application to Aromatic Acetals and Acylal
Suzuki, Hitomi,Yonezawa, Shuji,Mori, Tadashi
, p. 1535 - 1544 (2007/10/03)
Cyclic acetals derived from aromatic carbonyl compounds can be nitrated smoothly with nitrogen dioxide in ice-cooled dichloromethane or acetonitrile in the presence of ozone and magnesium oxide to give ortho- and para-nitro derivatives as the major product in good combined yields, the acetal ring as a protective group remaining almost intact.An acylal derived from benzaldehyde similarly undergoes nitration on the aromatic ring to give an isomeric mixture of three nitro compounds, in which the ortho and meta isomers predominate, while aromatic orthoesters are rapidly decomposed to give simply the parent esters.Ring nitration under neutral conditions has been interpreted in terms of a nonclassical mechanism, in which nitrogen trioxide is involved as the initial electrophile.
AN EXPEDITIOUS ROUTE TO MONOPROTECTED α-KETO ALDEHYDES WITH CONTROL OF REGICHEMISTRY
Babler, James H.
, p. 355 - 358 (2007/10/02)
Treatment of representative orthoesters (2) with pyruvonitrile (3) afforded the corresponding α,α-diethoxynitriles (4) in 65-85percent yields.Subsequent reduction of the latter using lithium aluminium hydride, followed by careful hydrolysis of the aldimine intermediates, led to the procurement of α,α-doalkoxy aldehydes (5) in 80-90percent yield.
