- A Direct Br?nsted Acid-Catalyzed Azidation of Benzhydrols and Carbohydrates
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Benzhydryl alcohols were converted into their corresponding diarylazidomethane analogues using azidotrimethylsilane (TMSN3) in the presence of a catalytic amount of a Br?nsted acid HBF4·OEt2. The azidation reactions proceeded in high yields and demonstrated excellent functional group tolerance to electron-donating and electron-withdrawing substituents. In addition, a range of unprotected functional groups including amine, amide, aldehyde and alcohol were well-tolerated. Furthermore, this methodology was successfully applied to carbohydrates for the preparation of the corresponding azide derivatives.
- Regier, Jeffery,Maillet, Robert,Bolshan, Yuri
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p. 2390 - 2396
(2019/04/14)
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- Gold-catalysed glycosylation reaction using an easily accessible leaving group
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Gold(iii)-catalysed glycosylation reaction has been developed by employing a new and easily accessible leaving group synthesized from ethyl cyanoacetate. Several nucleophiles like alcohols, thiols, allyltrimethylsilane, trimethylsilyl azide and triethylsilane have been reacted to make the corresponding glycosides in good yields and with marginal to excellent α-selectivity. This journal is
- Koppolu, Srinivasa Rao,Niddana, Ramana,Balamurugan, Rengarajan
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p. 5094 - 5097
(2015/05/13)
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- "click" synthesis of nonsymmetrical bis(1,2,3-triazoles)
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Chemical Fig. Repretation Unsymmetrically 1,1'-disubstituted 4,4'-bis-1 H-1,2,3-triazoles 4 have been prepared from 4-ethynyl-1,2,3-triazoles 5 and azides. Following a "double-click" strategy, two complementary approaches were implemented for the preparation of the key 4-ethynyltriazole Intermediates 5: (a) the stepwise Swern oxidatlon/Ohira-Bestman alkynylation of readily available 4-hydroxymethyl-1,2,3-triazoles 8 and (b) the stepwise cycloaddition of TMS-1,4-butadiyne 9. The method is highlighted by Its compatibility with orthogonally protected and functlonallzed saccharide-peptide hybrids and its ability to be extended to the trlsubstituted counterparts 12.
- Aizpurua, Jesus M.,Azcune, Itxaso,Fratila, Raluca M.,Balentova, Eva,Sagartzazu-Aizpurua, Malaien,Miranda, Jose I.
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supporting information; experimental part
p. 1584 - 1587
(2010/06/16)
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- "Click" saccharide/β-lactam hybrids for lectin inhibition
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(Figure Presented) Hybrid glycopeptide β-lactam mimetics designed to bind lectins or carbohydrate recognition domains in selectins have been prepared according to a "shape-modulating linker" design. This approach was implemented using the azide-alkyne "cl
- Palomo, Claudio,Aizpurua, Jesus M.,Balentova, Eva,Azcune, Itxaso,Santos, J. Ignacio,Jimenez-Barbero, Jesus,Canada, Javier,Miranda, Jose Ignacio
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supporting information; experimental part
p. 2227 - 2230
(2009/09/25)
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- Total synthesis of spicamycin
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The first total synthesis of one of the spicamycin congeners, SPM VIII (3), is described. A preliminary model study for construction of the characteristic N-glycoside linkage in spicamycin using tetra-O-benzyl-β-D-mannopyranosylamine (13) and halopurines 5 revealed that Pd-catalyzed conditions successfully provided the coupling products 14 and 15 in good yields. It was also shown that thermal anomerization of the N-glycosides easily occurred, which resulted in the predominant formation of the β-anomer as the thermodynamically favored compound, and the activation energy of anomerization of 15 was estimated to be ca. 30 kcal/mol. The novel aminoheptose unit of spicamycin 6 was prepared stereoselectively by carbon elongation of an acyclic aldehyde, prepared by ring cleavage reaction of a highly functionalized cyclohexane derived from naturally abundant myo-inositol. The Pd-catalyzed coupling reaction of the β-heptopyranosylamine 6 with protected 6-chloropurine 5d, followed by deprotection, provided spicamycin amino nucleoside 2, whose condensation with dodecanoylglycine completed the total synthesis of 3. This study confirmed the proposed unique structure of a novel nucleoside antibiotic.
- Suzuki, Tamotsu,Suzuki, Sayaka T.,Yamada, Iwao,Koashi, Yoshiaki,Yamada, Kazue,Chida, Noritaka
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p. 2874 - 2880
(2007/10/03)
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- Process for the preparation of azide derivatives
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A process for the preparation of azide derivatives useful as drugs, perfumes or intermediates of dyes by reacting an alcohol derivative with di-p-nitrophenyl phosphorazidate in the presence of 1,8-diazabicyclo[5.4.0]-7-undecene.
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- Efficient method for the one-pot azidation of alcohols using bis(p-nitrophenyl) phosphorazidate
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The direct stereoselective conversion of various alcohols and hexopyranoses into the corresponding alkyl azides and glycosyl azides, respectively, is efficiently accomplished by using bis(p-nitrophenyl) phosphorazidate and DBU.
- Mizuno, Masanori,Shioiri, Takayuki
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p. 2165 - 2166
(2007/10/03)
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