Adam M.-P. Pederson, Terry L. Price Jr, Daniel V. Schoonover, Carla Slebodnick, Harry W. Gibson
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引用次数: 4
Abstract
Two new cryptands, 2 and 4, were prepared from bis(m-phenylene)-32-crown-10 (BMP32) 5,5'-diacid chloride and dibenzo-30-crown-10 (DB30) 4,4'-diacid chloride, respectively, by reaction with pyridine-2,6-dimethanol. The resultant cryptands 2 and 4 have the ester moieties reversed from the previously reported isomers, 1 and 3. These “reverse” cryptands display lower association constants with viologen derivatives than the original cryptands; this is rationalized by the conjugation of the ester moieties with the aromatic rings, which reduces their electron-donating properties and offsets the increased basicity of the pyridyl nitrogen atoms. The crystal structure of the BMP32-based cryptand 2 indeed confirms the coplanarity of the ester and aromatic moieties and indicates that, as a result, the available cavity is quite small and that the pyridyl nitrogen atom points away from the cavity.
期刊介绍：
Heteroatom Chemistry brings together a broad, interdisciplinary group of chemists who work with compounds containing main-group elements of groups 13 through 17 of the Periodic Table, and certain other related elements. The fundamental reactivity under investigation should, in all cases, be concentrated about the heteroatoms. It does not matter whether the compounds being studied are acyclic or cyclic; saturated or unsaturated; monomeric, polymeric or solid state in nature; inorganic, organic, or naturally occurring, so long as the heteroatom is playing an essential role. Computational, experimental, and combined studies are equally welcome.
Subject areas include (but are by no means limited to):
-Reactivity about heteroatoms for accessing new products or synthetic pathways
-Unusual valency main-group element compounds and their properties
-Highly strained (e.g. bridged) main-group element compounds and their properties
-Photochemical or thermal cleavage of heteroatom bonds and the resulting reactivity
-Uncommon and structurally interesting heteroatom-containing species (including those containing multiple bonds and catenation)
-Stereochemistry of compounds due to the presence of heteroatoms
-Neighboring group effects of heteroatoms on the properties of compounds
-Main-group element compounds as analogues of transition metal compounds
-Variations and new results from established and named reactions (including Wittig, Kabachnik–Fields, Pudovik, Arbuzov, Hirao, and Mitsunobu)
-Catalysis and green syntheses enabled by heteroatoms and their chemistry
-Applications of compounds where the heteroatom plays a critical role.
In addition to original research articles on heteroatom chemistry, the journal welcomes focused review articles that examine the state of the art, identify emerging trends, and suggest future directions for developing fields.
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