Straightforward synthesis of a tetrasaccharide repeating unit corresponding to the O-antigen of Escherichia coli O16

• Manas Jana and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 1757–1762, doi:10.3762/bjoc.9.203

• stereoselective glycosylation of compounds 2 and 3 in the presence of a combination of N-iodosuccinimide (NIS) and triflic acid (TfOH) [18][19], followed by the removal of the p-methoxybenzyl (PMB) group in a one-pot reaction [17] by tuning the reaction conditions furnished the disaccharide acceptor 6 in 76

• mixture was cooled to −30 °C. To the cooled reaction mixture N-iodosuccinimide (NIS; 1.3 g, 5.77 mmol) and trifluoromethanesulfonic acid (TfOH; 50 μL) were added, and the mixture was stirred at the same temperature for 1 h. The temperature of the reaction mixture was raised to 0 °C and it was stirred at 0

• synthetic intermediates. Reagents: (a) N-iodosuccinimide (NIS), TfOH, CH2Cl2, MS 4 Å, −30 °C, 1 h, then 0 °C, 1 h, 76%; (b) NIS, TfOH, CH2Cl2/Et2O (1:3, v/v), MS 4 Å, −40 °C, 1 h, 73%; (c) 0.1 M CH3ONa, CH3OH, room temperature, 2 h, 94%; (d) NIS, TfOH, CH2Cl2, MS 4 Å, −20 °C, 1 h, 72%; (e) Et3SiH, 10% Pd/C

Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs

• Fabrice Chemla,
• Florian Dulong,
• Franck Ferreira and
• Alejandro Pérez-Luna

Beilstein J. Org. Chem. 2013, 9, 236–245, doi:10.3762/bjoc.9.28

• )enoates having pendant haloalkynes. Preparation of β-(propargyloxy)enoates having pendant haloalkynes. Reagents and conditions: (a) 2 (1.4 equiv), Et3N (4 equiv), NaI (10 mol %), CH2Cl2, 50 °C, sealed tube, 74% (3a), 87% (3c); (b) AgNO3 (1.5 equiv), N-iodosuccinimide (1.5 equiv), acetone, rt, 53% (3b

Glycosylation efficiencies on different solid supports using a hydrogenolysis-labile linker

• Mayeul Collot,
• Steffen Eller,
• Markus Weishaupt and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 97–105, doi:10.3762/bjoc.9.13

• toluene. Thioglycoside 35 was activated with N-iodosuccinimide (NIS) and triflic acid (TfOH) in dichloromethane and dioxane. In order to establish optimal reaction conditions, temperatures ranging from −40 °C to 25 °C were screened and the reaction time was varied between 15 and 45 minutes. After

Convergent synthesis of the tetrasaccharide repeating unit of the cell wall lipopolysaccharide of Escherichia coli O40

• Abhijit Sau and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2012, 8, 2053–2059, doi:10.3762/bjoc.8.230

• , which include (a) stereoselective [2 + 2] block glycosylation; (b) application of general glycosylation reactions by using thioglycosides as glycosyl donors and a combination of N-iodosuccinimide (NIS) and perchloric acid supported over silica (HClO4–SiO2) [17][18] as glycosyl activator; (c

• -benzylidene acetal with triethylsilane and iodine [22] furnished compound 6 in 82% yield. Stereoselective glycosylation of compound 6 with thioglycoside derivative 3 in the presence of a combination of N-iodosuccinimide (NIS) and HClO4–SiO2 [17] gave disaccharide derivative 7 in a 77% yield. Formation of

• at room temperature for 30 min under argon. The reaction mixture was cooled to −25 °C, and N-iodosuccinimide (NIS; 0.8 g, 3.55 mmol) and HClO4–SiO2 (25.0 mg) were added to it. After being stirred at same temperature for 1 h the reaction mixture was filtered through a Celite® bed and washed with

Automated synthesis of sialylated oligosaccharides

• Davide Esposito,
• Mattan Hurevich,
• Bastien Castagner,
• Cheng-Chung Wang and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2012, 8, 1601–1609, doi:10.3762/bjoc.8.183

• semi-protected oligosaccharide. The automated synthesis of 20 (Scheme 3) started with the glycosylation of resin-bound linker 17 with glucosamine building block 18 (2 × 5 equiv) [5] in the presence of N-iodosuccinimide and triflic acid. Fluorenylmethoxycarbonyl (Fmoc) removal was followed by

Synthesis and antifungal properties of papulacandin derivatives

• Marjolein van der Kaaden,
• Eefjan Breukink and
• Roland J. Pieters

Beilstein J. Org. Chem. 2012, 8, 732–737, doi:10.3762/bjoc.8.82

• primary alcohol to give 7 (Scheme 1). This compound was iodinated by using N-iodosuccinimide (NIS), and finally the free hydroxy group was protected with a pivaloyl group to give aryl iodide 12. Derivatives 13 and 14, providing alternative core structures, were prepared similarly. The glucose moiety at

Convergent synthesis of the tetrasaccharide repeating unit of the O-antigen of Shigella boydii type 9

• Abhishek Santra and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2011, 7, 1182–1188, doi:10.3762/bjoc.7.137

• disaccharide acceptor 2 in the presence of a combination of N-iodosuccinimide (NIS) and HClO4–SiO2 [25][26] furnished tetrasaccharide derivative 8 in 82% yield. Stereoselective formation of new α-glycosyl linkage in compound 8 was confirmed from the 1D and 2D NMR spectral analysis (presence of signals at δ

• the synthesized tetrasaccharide and its intermediates. Reagents: (a) acetic anhydride, sulfamic acid, 60 °C, 30 min, 91%; (b) Et3SiH, I2, 0–5 °C, 30 min, 82%. Reagents: (a) HClO4–SiO2, CH2Cl2, −15 °C, 1 h, 81%; (b) benzyl bromide, NaOH, n-Bu4NBr, THF, rt, 2 h, 91%. Reagents: (a) N-iodosuccinimide

When gold can do what iodine cannot do: A critical comparison

• Sara Hummel and
• Stefan F. Kirsch

Beilstein J. Org. Chem. 2011, 7, 847–859, doi:10.3762/bjoc.7.97

• , respectively. Consequently, Kirsch and co-workers described a reaction process using N-iodosuccinimide (NIS) instead of AuCl3 in an attempt to obtain 4-iodofuranones via an analogous iodonium-mediated cyclization [70]. With NIS as the electrophile at room temperature in CH2Cl2, the iodofuranone 4 was obtained

Benzyne arylation of oxathiane glycosyl donors

• Martin A. Fascione and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2010, 6, No. 19, doi:10.3762/bjoc.6.19

• turn the α-directing participating group into an anomeric leaving group reactive enough to partake in glycosylations. Thioglycosides are widely used as glycosyl donors [14][15], and many different reagents are available for their activaton including N-iodosuccinimide (NIS)/TMSOTf [16], dimethyl

Chemical synthesis using enzymatically generated building units for construction of the human milk pentasaccharides sialyllacto-N-tetraose and sialyllacto-N-neotetraose epimer

• Dirk Schmidt and
• Joachim Thiem

Beilstein J. Org. Chem. 2010, 6, No. 18, doi:10.3762/bjoc.6.18

• glycosylations employing triflic acid/N-iodosuccinimide. Easily accessible selectively protected lactoside derivatives served as acceptor disaccharides to give the corresponding human milk pentasaccharides in good yields. These were characterized by spectroscopic means in the form of their peracetylated

• by 6 catalyzed by N-iodosuccinimide and trifluoromethane sulfonic acid (as introduced by van Boom et al. [11]) gave the β,1-3-linked pentasaccharide 7 in 61% yield. About 5% of the corresponding α,1-3-linked compound and ca. 7% of the bis (β,1-3- and β,1-4-) linked octasaccharide were observed as

• and finally treatment with tert-butyldiphenylsilyl chloride and imidazole in DMF afforded the disaccharide 12 (cf. references [14][15]). After activation of the trisaccharide donor 10 with N-iodosuccinimide and trifluoromethanesulfonic acid, the disaccharide acceptor unit 12 could be glycosylated to

Shape- persistent macrocycle with intraannular alkyl groups: some structural limits of discotic liquid crystals with an inverted structure

• Sigurd Höger,
• Jill Weber,
• Andreas Leppert and
• Volker Enkelmann

Beilstein J. Org. Chem. 2008, 4, No. 1, doi:10.1186/1860-5397-4-1

• (model reactions with 4-methylanisole showed that a direct diiodination could not be obtained under the conditions we used; for example, with N-iodosuccinimide and FeCl3 we could obtain cleanly 2-iodo-4-methylanisole). Pd-catalyzed Hagihara-Sonogashira coupling with 15, deprotection of the