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Volumn 14, Issue 2, 2012, Pages 378-392

Critical assessment of the efficiency of chitosan biohydrogel beads as recyclable and heterogeneous organocatalyst for C–C bond formation

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EID: 84857173816     PISSN: 14639262     EISSN: 14639270     Source Type: Journal    
DOI: 10.1039/c1gc15925a     Document Type: Article
Times cited : (98)

References (82)
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    • The term “no conversion” has been generally adopted during the entire manuscript to indicate product formation below 1% as detected by NMR analysis
    • The term “no conversion” has been generally adopted during the entire manuscript to indicate product formation below 1% as detected by NMR analysis.
  • 36
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    • Such low reaction conversion was also observed if the CSHB were first stirred in the presence of acetone (30 min) before addition of the aldehyde
    • Such low reaction conversion was also observed if the CSHB were first stirred in the presence of acetone (30 min) before addition of the aldehyde.
  • 37
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    • general, aldol reactions may be catalyzed either by a base or an acid, where the nucleophile is an enolate anion or enol, respectively. In the latter case, catalytic protonation of the carbonyl oxygen increases the electrophilicity of the carbonyl carbon just enough so that it can be attacked by the enol, and promote the dehydration of the aldol product, as water is a good leaving group. Nevertheless, it is well known that aldol reactions proceed more efficiently under basic conditions where dehydration rarely takes place during the reaction since hydroxide is a poor leaving group
    • In general, aldol reactions may be catalyzed either by a base or an acid, where the nucleophile is an enolate anion or enol, respectively. In the latter case, catalytic protonation of the carbonyl oxygen increases the electrophilicity of the carbonyl carbon just enough so that it can be attacked by the enol, and promote the dehydration of the aldol product, as water is a good leaving group. Nevertheless, it is well known that aldol reactions proceed more efficiently under basic conditions where dehydration rarely takes place during the reaction since hydroxide is a poor leaving group.
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    • 2 and Ag(0), which could be further quantified by AAS
    • 2 and Ag(0), which could be further quantified by AAS.
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    • references therein
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    • references therein
    • Y. Hayashi Angew. Chem., Int. Ed. 2006 45 8103-8104 and references therein.
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    • Hayashi, Y.1
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    • 2O, 48 h, RT
    • 2O, 48 h, RT.
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    • 85034349017 scopus 로고    scopus 로고
    • 1H NMR analysis of the extracts did not show any signal corresponding to the reaction product, but only signals of the starting aldehyde (ca. 8 mol%)
    • 1H NMR analysis of the extracts did not show any signal corresponding to the reaction product, but only signals of the starting aldehyde (ca. 8 mol%).
  • 59
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    • references therein
    • F. A. Luzzio Tetrahedron 2001 57 915-945 and references therein.
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    • Luzzio, F.A.1
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    • Additional experiments have shown that 4 h is enough to achieve practically full conversion in DMSO
    • Additional experiments have shown that 4 h is enough to achieve practically full conversion in DMSO.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.