Isocyanid‐Synthese mit Diphosgen

Skorna, Giselher; Ugi, Ivar

doi:10.1002/ange.19770890423

Cited by 58 publications

(13 citation statements)

References 6 publications

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“…Although N ‐acyl amino acids are sensitive to epimerization, particularly when protected as esters, optically pure diastereomers were obtained after crystallization, as confirmed by a comparison of the optical rotations of the FAAs. The isocyanoalanyl–alanine methyl esters (IAAs) were prepared by the treatment of the N ‐formyl dipeptides with either phosphoryl chloride12 or diphosgene 13. The use of the latter reagent, however, resulted in a more efficient conversion; that is, yields of 60–90% were obtained versus 40–70% in the former case.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of polyisocyanides derived from alanine and glycine dipeptides

Cornelissen

Graswinckel

Adams

et al. 2001

J. Polym. Sci. A Polym. Chem.

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The synthesis and characterization of polymers derived from isocyanopeptides are described. Optically pure dipeptides based on alanine and glycine were equipped with an isocyano function and subsequently polymerized with a Ni(II) catalyst. Infrared and NMR spectroscopy indicated that the side chains of the polymers were connected by well-defined arrays of intramolecular hydrogen bonds. The weightaverage molecular weights of the polymers were determined by atomic force microscopy to be 200 -400 kg/mol (polydispersity index ϭ 1.4 -1.7).

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Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of polyisocyanides derived from alanine and glycine dipeptides

Cornelissen

Graswinckel

Adams

et al. 2001

J. Polym. Sci. A Polym. Chem.

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“…13 [27] was prepared according to the literature. Phenyl isonitrile was prepared according to published procedures [29] and stored at 4 8C. [4] (61.6 mg, 0.20 mmol) in THF was added dropwise.…”

Section: Methodsmentioning

confidence: 99%

Novel Initiators for Thermally and UV‐Triggered ROMP

Zhang

Wang

Lönnecke

et al. 2006

Macromolecular Symposia

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Summary: Novel ruthenium-based photoactive transition metal catalysts, i.e. [Ru(CF 3-CO 2 ) 2 (p-cymene)(IMes)] (2), [Ru(CF 3 CO 2 ) 2 (PhNC) 3 (IMes)] (3), [Ru(CF 3 CO 2 ) 2 (p-cymene) (IMesH 2 )] (4), [Ru(CF 3 CO 2 ) 2 (PhNC)) 3 (IMesH 2 )] (5), have been prepared and investigated for their use as initiators for the thermally and photo-initiated ring-opening metathesis polymerization (photo-ROMP). The polymerization behavior of the novel systems for both norborn-2-ene and functional monomers, such as norborn-5-ene-2-ylmethanol, has been investigated.

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“…This isocyanide was synthesized from la according to a modification of the method of Skorna and Ugi. 19 The procedure was as follows: Into a round-bottomed flask, equipped with a magnetic stirrer and a C 0 2/acetone reflux condenser kept at -30 °C were brought 4.35 g (30 mmol) of la, 7.05 mL (63.0 mmol) of dry N-methylmorpholine, and 50 mL of dry CH 2C12 as a solvent. At a tem perature of -30 to -40 °C, 1.81 mL (15.0 mmol) of diphosgene in 10 mL of dry C H 2C12 was introduced into the stirred reaction mixture over a period of approximately 2 h. The reaction was followed by TLC (silica gel, CHC13).…”

Section: Helical Configuration Of Poly(iminomethylenes) 1683mentioning

confidence: 99%

Helical configuration of poly(iminomethylenes). Synthesis and CD spectra of polymers derived from optically active isocyanides

Beijnen¹,

Nolte²,

Naaktgeboren³

et al. 1983

Macromolecules

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Each of nine chiral isocyanides, R*-N=C, in enantiomerically pure or almost pure form, is polymerized to the corresponding poly(iminomethylene), [R*-N=C<]n. The group R* either contains at least one substituent (carboxylic ester, phenyl, phosphinyl) or is unsaturated (C=C, C=C). The polymers are of the rigid-rod type with a helical main chain of carbon atoms. Because of the chirality of R*-N=C either the P or the M helix is preferentially formed. CD spectra and optical rotation at 578 nm are determined and compared with those of the model compounds R*-N=CH(i-C4H9) and the monomers. This comparison and earlier calculations on [i-C4H9-N=C<]n allowed the assignment to each polymer of the excess screw sense. The screw sense is also theoretically predicted by two approaches, a thermodynamic and a kinetic one. The latter approach gives an appreciably better fit with the experimental results.

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Isocyanid‐Synthese mit Diphosgen

Cited by 58 publications

References 6 publications

Synthesis and characterization of polyisocyanides derived from alanine and glycine dipeptides

Synthesis and characterization of polyisocyanides derived from alanine and glycine dipeptides

Novel Initiators for Thermally and UV‐Triggered ROMP

Helical configuration of poly(iminomethylenes). Synthesis and CD spectra of polymers derived from optically active isocyanides

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