<i>p</i>-Methoxybenzyl Ether Cleavage by Polymer-Supported Sulfonamides

Hinklin, Ronald J.; Kiessling, Laura L.

doi:10.1021/ol025514c

Cited by 27 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compounds 3aa ,8f 3ab ,8f 3ac ,12 3ad ,13 3ae ,8f 3ba ,14 3be ,8f,9d 3da ,8a,15 3dd ,8a,16 3ea ,17 3eb ,18 3ed ,18 3ee ,9b 3fa ,19 3ga ,15 3ha ,20 and 3ia 21 had been reported previously, and their identities were confirmed by comparison of their melting points and spectroscopic data with the reported data. Characterization data for the new compounds 3bb , 3bc , 3bd , 3ca , 3cb , and 3cd are shown below.…”

Section: Methodssupporting

confidence: 80%

Phosphotungstic Acid Catalyzed Amidation of Alcohols

Wang

Shen

2008

Eur J Org Chem

View full text Add to dashboard Cite

Mild nucleophilic substitution reactions of benzhydrylic, benzylic, allylic, and simple aliphatic alcohols with sulfonamides, benzamide, and 4‐nitroaniline in the presence of 12‐phosphotungstic acid as an efficient, eco‐friendly, cheap, and air‐ and moisture‐tolerant catalyst for the construction of C–N bonds has been investigated. The amine derivatives were obtained in good yields (up to 98 %). The reusable nature of the 12‐phosphotungstic acid makes this protocol more attractive.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

show abstract

Section: Methodssupporting

confidence: 80%

Phosphotungstic Acid Catalyzed Amidation of Alcohols

Wang

Shen

2008

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…The previously employed DDQ oxidation21 decomposed the oligosaccharide. Cerium ammonium nitrate (CAN) oxidation29 or the combination of p -tolyl sulfonamide and triflic acid30 also failed to lead to the desired penta-ol. To circumvent this problem, the 6-hydroxyl group liberation and oxidation state adjustment were performed on disaccharide 6 (Scheme 2b).…”

Section: Resultsmentioning

confidence: 99%

Chemical Synthesis of a Hyaluronic Acid Decasaccharide

Kamat

Huang

et al. 2009

J. Org. Chem.

View full text Add to dashboard Cite

The chemical synthesis of a hyaluronic acid decasaccharide using the pre-activation based chemoselective glycosylation strategy is described. Assembly of large oligosaccharides is generally challenging due to the increased difficulties in both glycosylation and deprotection. Indeed, the same building blocks previously employed for hyaluronic acid hexasaccharide syntheses failed to yield the desired decasaccharide. After extensive experimentation, the decasaccharide backbone was successfully constructed with an overall yield of 37% from disaccharide building blocks. The trichloroacetyl group was used as the nitrogen protective group for the glucosamine units and the addition of TMSOTf was found to be crucial to suppress the formation of trichloromethyl oxazoline side-product and enable high glycosylation yield. For deprotections, the combination of a mild basic condition and the monitoring methodology using 1H-NMR allowed the removal of all base-labile protective groups, which facilitated the generation of the fully deprotected HA decasaccharide.

show abstract

“…Based on these observations, i-Pr 2 NEt was effective only for the esterification of aromatic carboxylic acids. With PMB-protected 5-acylquinates (10a, 14a, 16a, and 17) in hand, we examined mild deprotection reactions (TFA/PhOH, 16 TfOH/p-TolSO 2 NH 2 /dioxane, 17 CBr 4 /MeOH, 18 CeCl 3 $7H 2 O/NaI/ CH 3 CN, 19 and CAN/H 2 O/CH 3 CN 20 ). However, the desired deprotection products were not obtained cleanly in any case.…”

Section: Esterification Of 5-oh Of Pmb Quinatementioning

confidence: 99%