Showing papers on "Ferrier rearrangement published in 2012"
TL;DR: Electron-rich arene-bearing hexahydroquinolizin-2-ones are formed in good yields and can be converted into indole alkaloids in only a few steps.
Abstract: Golden Cascade: With a tethered, electron-rich arene as the internal nucleophile, a gold-catalyzed amide cyclization to an alkyne initiates a cascade process that ends with a Ferrier rearrangement. Electron-rich arene-bearing hexahydroquinolizin-2-ones are formed in good yields and can be converted into indole alkaloids in only a few steps.
44 citations
TL;DR: F-CeNA modified oligonucleotides were significantly more stable against digestion by snake venom phosphodiesterases (SVPD) as compared to unmodified DNA, 2'-fluoro RNA (FRNA), 2'-methoxyethyl RNA (MOE), and FHNAmodified oligon nucleotides.
Abstract: We report the design and synthesis of 2′-fluoro cyclohexenyl nucleic acid (F-CeNA) pyrimidine phosphoramidites and the synthesis and biophysical, structural, and biological evaluation of modified oligonucleotides. The synthesis of the nucleoside phosphoramidites was accomplished in multigram quantities starting from commercially available methyl-d-mannose pyranoside. Installation of the fluorine atom was accomplished using nonafluorobutanesulfonyl fluoride, and the cyclohexenyl ring system was assembled by means of a palladium-catalyzed Ferrier rearrangement. Installation of the nucleobase was carried out under Mitsunobu conditions followed by standard protecting group manipulations to provide the desired pyrimidine phosphoramidites. Biophysical evaluation indicated that F-CeNA shows behavior similar to that of a 2′-modified nucleotide, and duplexes with RNA showed slightly lower duplex thermostability as compared to that of the more rigid 3′-fluoro hexitol nucleic acid (FHNA). However, F-CeNA modified ol...
36 citations
TL;DR: A temperature-controlled mechanism switch between the Al(OTf)(3)-catalysed direct addition of alcohols or the Ferrier rearrangement reactions in some glycals is presented.
Abstract: A temperature-controlled mechanism switch between the Al(OTf)(3)-catalysed direct addition of alcohols or the Ferrier rearrangement reactions in some glycals is presented. The scope and limitations are investigated as are the influence of the stereochemistry and nature of the protecting groups on the glycal substrate.
28 citations
TL;DR: By using iron(III) triflate as catalyst, an improved method for the synthesis of 2,3-unsaturated-O-glycosides has been established in this article.
26 citations
TL;DR: An efficient catalyst for Ferrier rearrangement and hetero-Michael addition was successfully generated from a sacrificial zirconium anode into media containing reactants for these reactions as discussed by the authors.
15 citations
TL;DR: In this article, the reaction of 3-hydroxy free glycals with O- or N-nucleophiles under Mitsunobu reaction conditions proceeded to produce 2,3-unsaturated glycosides in good to high yield and moderate stereoselectivity.
10 citations
TL;DR: In this paper, an expedient synthetic method for O-glycosidation of 3,4,6-tri- O-acetyl -D- glucal for the synthesis of 2,3-unsaturated O- glycosides using bromodimethylsulfonium bromide (BDMS) as a pre-catalyst through Ferrier rearrangement.
Abstract: An expedient synthetic method has been developed for O-glycosidation of 3,4,6-tri- O-acetyl -D- glucal for the synthesis of 2,3-unsaturated O-glycosides using bromodimethylsulfonium bromide (BDMS) as a pre-catalyst through Ferrier rearrangement. Some of the salient features of the present protocol are mild reaction conditions, shor ter reaction time, easy work-up procedure, high α-selectivity and good yields.
3 citations
TL;DR: The cascade reaction of amides tethered with a terminal alkyne moiety proceeds via a gold-catalyzed amide cyclization followed by a Ferrier rearrangement.
Abstract: The cascade reaction of amides tethered with a terminal alkyne moiety proceeds via a gold-catalyzed amide cyclization followed by a Ferrier rearrangement.
1 citations
TL;DR: A series of unsaturated O-glucosides were obtained from acetyl-Dglucal (I) in good yields and high anomeric selectivity.
Abstract: A series of unsaturated-O-glucosides are obtained from acetyl-D-glucal (I) in good yields and high anomeric selectivity.
1 citations
TL;DR: The reaction of benzyl protected glycal (I) with both aliphatic and aromatic alcohols in the presence of Al(O-Tf)3 proceeds either via addition or via Ferrier rearrangement depending on the reaction temperature as discussed by the authors.
Abstract: The reaction of benzyl protected glycal (I) with both aliphatic and aromatic alcohols in the presence of Al(O-Tf)3 proceeds either via addition or via Ferrier rearrangement depending on the reaction temperature.