- 1,3-oxazinan-2-ones from amines and 1,3-diols through dialkyl carbonate chemistry
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A one-pot green synthesis of 1,3-oxazinan-2-ones from amines and 1,3-diols in the presence of a dialkyl carbonate and potassium tert-butoxide is described. Four dialkyl carbonates were utilised: dimethyl carbonate, diethyl carbonate, diprop-2-yl carbonate, and tert-butyl methyl carbonate. The more hindered the dialkyl carbonate used, the higher the yield of 1,3-oxazinan-2-one. Four 1,3-diols were reacted having primary-primary, primary-secondary, primary-tertiary, and secondary-tertiary functionalities, with the yield of oxazinanone decreasing with increasing hindrance of the diol. In the case of the diols containing primary and either secondary or tertiary functionality, the substituent(s) were selectively found in the 6-position of the so-formed oxazinanone. The optimized conditions were then employed with different nucleophiles, namely phenylhydrazine, aniline, and n-octylamine.
- McElroy, Conrobert,Aricò, Fabio,Tundo, Pietro
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- Damage and Repair in Informational Poly(N-substituted urethane)s
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The degradation and repair of uniform sequence-defined poly(N-substituted urethane)s was studied. Polymers containing an ω-OH end-group and only ethyl carbamate main-chain repeat units rapidly degrade in NaOH solution through an ω→α depolymerization mechanism with no apparent sign of random chain cleavage. The degradation mechanism is not notably affected by the nature of the side-chain N-substituents and took place for all studied sequences. On the other hand, depolymerization is significantly influenced by the molecular structure of the main-chain repeat units. For instance, hexyl carbamate main-chain motifs block unzipping and can therefore be used to control the degradation of specific sequence sections. Interestingly, the partially degraded polymers can also be repaired; for example by using a combination of N,N′-disuccinimidyl carbonate with a secondary amine building-block. Overall, these findings open up interesting new avenues for chain-healing and sequence editing.
- Charles, Laurence,Lutz, Jean-Fran?ois,Mondal, Tathagata
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supporting information
p. 20390 - 20393
(2020/09/21)
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- New simple synthesis of N-substituted 1,3-oxazinan-2-ones
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An efficient and simple synthesis of N-substituted 1,3-oxazinan-2-ones was developed that involves a three-component, one-pot reaction of readily available tetraethylammonium bicarbonate, 1,3-dibromopropane, and a primary amine in methanol at room temperature. l-Alanine can be used as the amino component to give the chiral product (2S)-2-(2-oxo-1,3-oxazinan-3-yl)propanoic acid. Georg Thieme Verlag Stuttgart ? New York.
- Trifunovic, Sreko,Dimitrijevic, Dejana,Vasic, Gordana,Radulovic, Niko,Vukicevic, Mirjana,Heinemann, Frank W.,Vukicevic, Rastko D.
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experimental part
p. 943 - 946
(2010/04/30)
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- The Cycloaddition of Heterocumulenes to Oxetanes in the Presence of Catalytic Amounts of Tetraphenylstibonium Iodide
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The cycloadditions of carbon dioxide, isocyanates and carbodiimides to oxetanes proceeded in the presence of catalytic amounts of tetraphenylstibonium iodide (1) under mild conditions, affording the corresponding six-membered heterocycles; 1,3-dioxan-2-ones, 1,3-oxazin-2-ones and 1,3-oxazin-2-imines in good yields, respectively.Moreover, the cycloaddition of 2-phenyloxetane proceeded via predominant ring-cleavage at substituted site.
- Fujiwara, Masahiro,Baba, Akio,Matsuda, Haruo
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p. 1659 - 1663
(2007/10/02)
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- Formation of N-Tributylstannyl Heterocycle from Bis(tributyltin) Oxide and ω-Haloalkyl Isocyanate. One-Pot Convenient Synthesis of 2-Oxazolidinones and Tetrahydro-2H-1,3-oxazin-2-one
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Novel types of compounds, N-tributylstannyl-2-oxazolidinone (4a) and tetrahydro-2H-1,3-oxazin-2-one (4b), are formed from the adduct of (n-Bu3Sn)2O (1) with ω-haloalkyl isocyanate (2), and the subsequent coupling reaction with alkyl halides gives a variety of N-substituted 2-oxazolidinones and tetrahydro-2-oxazinones in a one-pot procedure.Both the cyclization and the coupling reaction proceed quantitatively in the presence of HMPA which enhances the reactivity of the Sn-heteroatom bond by coordination.
- Shibata, Ikuya,Nakamura, Kenji,Baba, Akio,Matsuda, Haruo
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p. 853 - 859
(2007/10/02)
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- NOVEL USE OF ORGANOTIN HALIDE-BASE COMPLEX IN ORGANIC SYNTHESIS. CYCLOADDITION REACTION OF OXETANE WITH ISOCYANATES.
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Cycloadditions of oxetanes with isocyanates were markedly accelerated by the complex of Bu2SnI2 and Ph3P=O which could be readily handled and hardly caused a trimerization of isocyanates, yielding oxazin-2-ones under neutral and mild reaction conditions.
- Baba, Akio,Shibata, Ikuya,Fujiwara, Masahiro,Matsuda, Haruo
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p. 5167 - 5170
(2007/10/02)
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