High-pressure-promoted condensation of isothiocyanates with aminopyridines: efficient synthesis of pyridine–thiourea conjugates as building blocks for hydrogen-bonding receptors

Kumamoto, Koji; Misawa, Yoshihiro; Tokita, Sumio; Kubo, Yuji; Kotsuki, Hiyoshizo

doi:10.1016/s0040-4039(01)02295-x

Cited by 31 publications

(15 citation statements)

References 13 publications

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“…The formation of symmetrical thioureas is often observed in the reaction of isothiocyanates with amines due to the reversibility of the reaction, which cross-splits the dissymmetrical thiourea into the isothiocyanate of the engaged amine and amine of the engaged isothiocyanate. 42 The very high selectivity of the reaction might arise from the presence of the sulfur atom of the thiazolinethione, which might strongly direct the possible decomposition of the thiourea towards the initial isothiocyanate and amine through intramolecular hydrogen bond. A noticeable exception, which supports the above argument, was observed in the case of the reaction between 3 and the thiazoline-2-one analogue of 2.…”

Section: Synthesismentioning

confidence: 99%

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives

et al. 2006

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The synthesis of a limited series of non-racemic atropisomeric 1-(2-(4-methyl-2-thioxothiazol-3(2H)-yl)phenyl)-3-(hetero)aryl-(thio)ureas is described. Using NMR titration experiments monitoring the shift of the two NH of the (thio)urea and the C-5 hydrogen of the heterocycle, the binding constants for some optically pure (thio)-ureas with the enantiomers of N-protected amino acid tetrabutylammonium salts were determined in CD3CN. The obtained enantioselectivities were modest. Contrary to what was expected on the basis of the NH acidity in thiourea versus urea group, the association constants were smaller with the thiourea than with the corresponding urea. X-ray data, DFT calculations, and NMR provided the explanation of that unexpected behavior: the urea presents a pre-organized (Z,Z) conformation suitable for a double hydrogen bond with the carboxylate anion, the thiourea presents a (Z,E) conformation, which must be reorganized in a constrained (Z,Z) conformation in the complex. An intramolecular hydrogen bond between one NH and the thiocarbonyl group of the heterocycle, which is present in the thiourea and absent in the urea, might also contribute to the smaller K(ass) for the thiourea. The possible implication of these observations in the field of bifunctional organocatalysis is briefly discussed.

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Section: Synthesismentioning

confidence: 99%

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives

et al. 2006

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“…Compounds with a thiourea group have often been used to design and synthesize biomimetic receptors for phosphate, with several research groups having reported artificial receptors for phosphate using this binding unit (Nishizawa et al 1999;Kumamoto et al 2002;Aoki et al 2003). We have also reported phosphate imprinted polymers in which this binding mechanism was introduced (Kugimiya et al 2006).…”

Section: Binding Activities Of Imprinted Polymersmentioning

confidence: 98%

Selective Recovery of Phosphate from River Water Using Molecularly Imprinted Polymers

Kugimiya

Takei

2008

Analytical Letters

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Phosphate-selective molecularly imprinted polymers were prepared using N-allyl-N 0 -methyl-thiourea or 1-allyl-2-thiourea as functional monomers, and the binding ability and selectivity of the polymers were evaluated. River water collected from agricultural use was the test sample. Though the water included some impurities, 65% of the phosphate was recovered from the imprinted polymer prepared using Nallyl-N 0 -methyl-thiourea as the functional monomer, while on the other hand, the binding of other anions was scarcely low. The imprinted polymer showed selective binding to phosphate and indicated the phosphate recovery material from river water.

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“…Typically, a solution of 4-nitrobenzoyl isothiocyanates (0.01 mol) in 50 mL of dichloromethane was cooled to 0 C, followed by the addition of 3-nitroaniline (0.01 mol) with continuous stirring for 1 h under an inert atmosphere. 30,31 The precipitates were first filtered and then washed with 1% HCl, distilled water and brine. After that, the product was dried under vacuum yielding the solid product (NBNPT) with 95% yield.…”

Section: Monomer Synthesismentioning

confidence: 99%

Synthesis and thermal behavior of novel poly(thiourea-amide)s derived from 1-(4-aminobenzoyl)-3- (3-aminophenyl) thiourea

Kausar

Zulfiqar

Ishaq

et al. 2011

High Performance Polymers

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High-pressure-promoted condensation of isothiocyanates with aminopyridines: efficient synthesis of pyridine–thiourea conjugates as building blocks for hydrogen-bonding receptors

Cited by 31 publications

References 13 publications

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives

Selective Recovery of Phosphate from River Water Using Molecularly Imprinted Polymers

Synthesis and thermal behavior of novel poly(thiourea-amide)s derived from 1-(4-aminobenzoyl)-3- (3-aminophenyl) thiourea

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High-pressure-promoted condensation of isothiocyanates with aminopyridines: efficient synthesis of pyridine–thiourea conjugates as building blocks for hydrogen-bonding receptors

Cited by 31 publications

References 13 publications

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller Kass with thiourea than urea derivatives

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller Kass with thiourea than urea derivatives

Selective Recovery of Phosphate from River Water Using Molecularly Imprinted Polymers

Synthesis and thermal behavior of novel poly(thiourea-amide)s derived from 1-(4-aminobenzoyl)-3- (3-aminophenyl) thiourea

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Product

Resources

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Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives

Non‐racemic atropisomeric (thio)ureas as neutral enantioselective anion receptors for amino‐acid derivatives: Origin of smaller K_ass with thiourea than urea derivatives