- Convenient Synthesis of 2-Amino-1,8-naphthyridines, Building Blocks for Host-Guest and Self-Assembling Systems
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Application of the Reimer-Tiemann reaction to 2,6-diaminopyridine afforded a 26percent yield of 2,6-diaminopyridine-3-carboxaldehyde (4) and a small amount (4percent) of 2,6-diaminopyridine-3,5-dicarboxaldehyde.Alternatively, conversion of 2,6-diaminopyridine to 2,6-bis(pivaloylamino)pyridine (6), directed lithiation with n-butyllithium, treatment with N-formylmorpholine, and hydrolysis produced 4 in 67 percent overall yield.The Friedlaender condensation of 4 with a variety of activated and unactivated ketones afforded 2-amino-1,8-naphthyridines and bis(2-amino-1,8-naphthyridines) in moderate to good yields, providing a convenient synthesis of useful building blocks for new host-guest and self-assembling systems.
- Fenlon, Edward E.,Murray, Thomas J.,Baloga, Monica H.,Zimmerman, Steven C.
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- NOVEL ANTIMALARIAL AGENT CONTAINING HETEROCYCLIC COMPOUND
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Disclosed herein are diaminopyridine compounds or pharmaceutically acceptable salts thereof having antimalarial activation effect.
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Paragraph 0057; 0071-0072
(2021/07/31)
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- Independently Tuned Frontier Orbital Energy Levels of 1,3,4,6,9b-Pentaazaphenalene Derivatives by the Conjugation Effect
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Herein reported are syntheses and the unique substituent effect in 1,3,4,6,9b-pentaazaphenalene (5AP) derivatives. We developed the new synthetic route via (N,N-pyridine-2,6-diyl)bisamides, which enabled us to prepare a variety of substituted 5APs and to
- Watanabe, Hiroyuki,Tanaka, Kazuo,Chujo, Yoshiki
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p. 2768 - 2778
(2019/02/26)
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- Site-Selective C–H Functionalization of (Hetero)Arenes via Transient, Non-symmetric Iodanes
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Fosu, Hambira, and colleagues describe the direct C–H functionalization of medicinally relevant arenes or heteroarenes. This strategy is enabled by transient generation of reactive, non-symmetric iodanes from anions and PhI(OAc)2. The site-selective incorporation of Cl, Br, OMs, OTs, and OTf to complex molecules, including within medicines and natural products, can be conducted by the operationally simple procedure included herein. A computational model for predicting site selectivity is also included. The discovery of new medicines is a time- and labor-intensive process that frequently requires over a decade to complete. A major bottleneck is the synthesis of drug candidates, wherein each complex molecule must be prepared individually via a multi-step synthesis, frequently requiring a week of effort per molecule for thousands of candidates. As an alternate strategy, direct, post-synthetic functionalization of a lead candidate could enable this diversification in a single operation. In this article, we describe a new method for direct manipulation of drug-like molecules by incorporation of motifs with either known pharmaceutical value (halides) or that permit subsequent conversion (pseudo-halides) to medicinally relevant analogs. This user-friendly strategy is enabled by combining commercial iodine reagents with salts and acids. We expect this simple method for selective, post-synthetic incorporation of molecular diversity will streamline the discovery of new medicines. A strategy for C–H functionalization of arenes and heteroarenes has been developed to allow site-selective incorporation of various anions, including Cl, Br, OMs, OTs, and OTf. This approach is enabled by in situ generation of reactive, non-symmetric iodanes by combining anions and bench-stable PhI(OAc)2. The utility of this mechanism is demonstrated via para-selective chlorination of medicinally relevant arenes, as well as site-selective C–H chlorination of heteroarenes. Spectroscopic, computational, and competition experiments describe the unique nature, reactivity, and selectivity of these transient, unsymmetrical iodanes.
- Fosu, Stacy C.,Hambira, Chido M.,Chen, Andrew D.,Fuchs, James R.,Nagib, David A.
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supporting information
p. 417 - 428
(2019/02/14)
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- Understanding the effects of preorganization, rigidity, and steric interactions in synthetic barbiturate receptors
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Synthetic barbiturate receptors have been utilized for many applications due to their high binding affinities for complementary guests. Although interest in this class of receptors spans from supramolecular to materials chemistry, the effects of receptor steric bulk and preorganization on guest binding affinity has not been studied systematically. To investigate the roles that steric bulk and preorganization play in guest binding, we prepared a series of 12 deconstructed Hamilton receptors with varying degrees of steric bulk and preorganization. Both diethylbarbital and 3-methyl- 7-propylxanthine were investigated as guests for the synthetic receptors. The stoichiometry of guest binding was investigated using Job plots for each host-guest pair, and 1H NMR titrations were performed to measure the guest binding affinities. To complement the solution-state studies, DFT calculations at the B3LYP/6-31+G(d,p) level of theory employing the IEF-PCM CHCl3 solvation model were also performed. Calculated guest binding energies correlated well with the experimental findings and provided additional insight into the factors influencing guest binding. Taken together, the results presented highlight the interplay between preorganization and steric interactions in establishing favorable interactions for self-assembled hydrogenbonded systems.
- McGrath, Jacqueline M.,Pluth, Michael D.
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p. 711 - 719
(2014/04/03)
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- Rhodium(III)-catalyzed oxidative olefination of pyridines and quinolines: Multigram-scale synthesis of naphthyridinones
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A Rh(III)-catalyzed oxidative olefination of pyridines and quinolines has been achieved. This method has a broad substrate scope and has been applied to the expeditious, multigram-scale synthesis of naphthyridinones.
- Zhou, Jun,Li, Bo,Hu, Fang,Shi, Bing-Feng
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supporting information
p. 3460 - 3463
(2013/07/26)
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- COMPOSITION FOR AGRICULTURAL USE FOR CONTROLLING OR PREVENTING PLANT DISEASES CAUSED BY PLANT PATHOGENS
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Disclosed is a composition for agricultural use, which is used for controlling or preventing plant diseases caused by plant pathogens. The composition for agricultural use contains a compound represented by formula (1), a salt thereof or a hydrate of the compound or the salt. (1) [In the formula, Z represents an oxygen atom, a sulfur atom or NRz; and E represents a furyl group, a thienyl group, a pyrrolyl group, a tetrazolyl group, a thiazolyl group, a pyrazolyl group, a phenyl group or the like.]
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Page/Page column 265-266
(2010/11/19)
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- Structural effects on the stability of some hydrogen-bonded complexes with nucleobases
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The effect that additional groups flanking the hydrogen bond donor/acceptor arrays have on the association constants (K(a)) of complexes of chloroform-soluble thymine and adenine derivatives has been investigated by NMR shift titration. Constants for thym
- Yu, Lianhe,Schneider, Hans-Joerg
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p. 1619 - 1625
(2007/10/03)
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