Showing papers on "Ferrier rearrangement published in 2014"
TL;DR: The results of experiments and theoretical studies fully support the proposed mechanism of the present anti- and enantioselective APF rearrangement.
Abstract: The precise mechanism of the highly anti- and enantioselective aza-Petasis–Ferrier (APF) rearrangement of hemiaminal vinyl ethers catalyzed by a chiral phosphoric acid was investigated by undertaking experimental and theoretical studies. The APF rearrangement is characterized by the following unique mechanistic features: (i) efficient optical kinetic resolution of the starting racemic hemiaminal vinyl ether, (ii) enantioconvergent process from racemic hemiaminal vinyl ethers to optically active β-amino aldehyde products, and (iii) anomalous temperature effects on the enantioselectivity (enantioselectivity increases as reaction temperature increases). The following experiments were conducted to elucidate the unique mechanistic features as well as to uncover the overall scheme of the present rearrangement: (A) X-ray crystallographic analysis of the recovered hemiaminal vinyl ether to determine its absolute configuration, (B) rearrangements of enantiomerically pure hemiaminal vinyl ethers to validate the ste...
40 citations
TL;DR: In this article, a new catalyst system comprising AuCl3 and phenylacetylene was developed to promote the Ferrier rearrangement of glycals and 2-acetoxymethyl glycals with different nucleophiles, and also the O-glycosylation of 1-O-acetyl sugars.
34 citations
TL;DR: The inhibitory activities of the synthesized molecules were tested against commercially available enzymes, which revealed the sugar-piperidine and sugar- pyran hybrids as potent and selective inhibitors.
Abstract: A few bicyclic hybrid sugar molecules comprising of oxa-aza, oxa-oxa, and oxa-carbasugar fused skeletons were designed and synthesized from C-2 acetoxyglucal involving Ferrier rearrangement, Grignard addition, and ring-closing metathesis as key steps. The inhibitory activities of the synthesized molecules were tested against commercially available enzymes, which revealed the sugar–piperidine and sugar–pyran hybrids as potent and selective inhibitors.
32 citations
TL;DR: In this paper, a novel method for synthesizing 2,3-unsaturated glycosides using a handy and eco-friendly immobilized catalyst, FeCl3·6H2O/C.
21 citations
TL;DR: In this paper, recent developments in the use of promoters for the Ferrier rearrangement of O-, N-, C- and S-nucleophiles with glycals are discussed.
Abstract: Review: recent developments in the use of promoters for the Ferrier rearrangement of O-, N-, C- and S-nucleophiles with glycals; <250 refs.
18 citations
TL;DR: A carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields with high selectivity and for the synthesis of a orthogonally protected 2-amino-2-deoxy-C-glycoside.
Abstract: A carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields with high selectivity. The versatility of this method has been demonstrated by applying it to differently protected glycals and by employing several nucleophiles. The obtained C-allyl glycoside has been utilized for the synthesis of a orthogonally protected 2-amino-2-deoxy-C-glycoside.
16 citations
TL;DR: This approach provides a wide range of β-keto-functionalized 2,3-unsaturated C-glycosides in moderate to good yields and good selectivities are mainly observed with the use of D-galactal along with bulkier β- keto acids bearing phenyl moieties.
Abstract: An efficient iron-catalyzed decarboxylative C-glycosylation of glycals with β-keto acids via decarboxylative Ferrier rearrangement reaction has been established. This approach provides a wide range of β-keto-functionalized 2,3-unsaturated C-glycosides in moderate to good yields. Good selectivities are mainly observed with the use of D-galactal along with bulkier β-keto acids bearing phenyl moieties.
14 citations
TL;DR: In this article, the sigma-Ferrier ring expansion of carbohydrate derived vinylcyclopropanes (VCPs) under electrophilic conditions mediated by chloramine-T and a phase-transfer catalyst was investigated.
13 citations
TL;DR: Au-catalyzed cycloisomerization of aryl propargyl ethers provides controlled transition from alkyne to carbonyl chemistry followed up by a Petasis-Ferrier rearrangement/aromatization cascade leading to substituted biaryls with functionalized naphthalene cores as mentioned in this paper.
11 citations
TL;DR: In this article, a series of 2,3-unsaturated glucosides have been synthesized from 3,4,6-tri-O-acetyl-d-glucal.
10 citations
TL;DR: A number of recently reported methods for the synthesis of spiroacetals are discussed in this paper, including their application in synthesis of natural products containing the Spiroacetal scaffold, which has attracted attention from the synthetic community, both because of the synthetic challenge of complex SPI natural product scaffolds, as well as the drive to develop and improve existing methods.
Abstract: The selective and efficient synthesis of spiroacetals has attracted attention from the synthetic community, both because of the synthetic challenge of complex spiroacetal natural product scaffolds, as well as the drive to develop and improve existing methods. A number of recently reported methods for the synthesis of spiroacetals are discussed, including their application in the synthesis of natural products containing the spiroacetal scaffold.
TL;DR: In this paper, the first report on aza-Ferrier rearrangement using molecular iodine is presented, which makes this method simple, convenient, and cost-effective, and the use of iodine makes the method simple and convenient.
TL;DR: In this paper, 1-C-alkynyl sugars are prepared from 2-acetoxy-glucal triacetate and Dicobalt complexes of these sugar acetylenes can stabilize the anomeric carbenium cations, which promote the Ferrier-type rearrangement through the 5,6-dehydro precursors to afford alkynyl cyclohexanones after decomplexation.
TL;DR: In this paper, the synthesis of carotenoid glucosides and deoxyglucosides using the acetimidate method and the Ferrier rearrangement, respectively, was described.
TL;DR: In this paper, Ferrier rearrangement, azide reduction, intramolecular cyclization, and Grignard reaction were used to synthesize deoxoprosopinine and (+)-2-epi-deoxoprinine starting from D-glycals.
TL;DR: Cyanuric chloride has been found to be an efficient catalyst for the synthesis of 2,3-unsaturated O-glycosides from the reaction of 3,4,6-tri-O-acetyl-D-glucal and a wide range of alcohols in dichloromethane at room temperature.
Abstract: Cyanuric chloride has been found to be an efficient catalyst for the synthesis of 2,3-unsaturated O-glycosides from the reaction of 3,4,6-tri-O-acetyl-D-glucal and a wide range of alcohols in dichloromethane at room temperature. The experimental procedure is simple, and the products are obtained in high yields.
01 Apr 2014
TL;DR: I2 is an effective promoter for the synthesis of 2,3-unsaturated glycosides via Ferrier glycosylation using metal-free reactions with good α-selectivity for O-glycosylated Fmoc amino acid building blocks.
Abstract: I2 is an effective promoter for the synthesis of 2,3-unsaturated glycosides via Ferrier glycosylation. This reaction was used in the present work for the synthesis of O-glycosylated Fmoc amino acid building blocks. This metal-free reaction afforded the desired products with good to excellent yields with good α-selectivity. c 2013 Institute of Chemistry, Slovak Academy of Sciences
TL;DR: Sulfuric acid immobilized on silica gel (H2SO4-SiO2) was used as an efficient and convenient promoter for Ferrier-type rearrangement of 3,4,6-tri-O-benzyl-dglucal in CH2Cl2 as mentioned in this paper.
Abstract: Sulfuric acid immobilized on silica gel (H2SO4-SiO2) was used as an efficient and convenient promoter for Ferrier-type rearrangement of 3,4,6-tri-O-benzyl-d-glucal in CH2Cl2, which is a difficult donor for this type of reaction. The acceptors include primary alcohols, secondary alcohols, pentanol, halogenated alcohol, sterols, thiol, and 2-naphthol. Thus, 2,3-unsaturated glycosides were obtained rapidly ( 62%) in good α-selectivity (α/β>4.2:1) under mild conditions.
TL;DR: The new reagent system is used for the synthesis of 2-nitroglycals from various protected glycals and can also be applied to non-carbohydrate olefins.
Abstract: The new reagent system is used for the synthesis of 2-nitroglycals from various protected glycals and can also be applied to non-carbohydrate olefins.
TL;DR: In this paper, a few bicyclic hybrid sugar molecules comprising of oxa-aza, oxaoxa, and oxa carbasugar fused skeletons were designed and synthesized from C-2 acetoxyglucal involving Ferrier rearrangement, Grignard addition, and ring-closing metathesis as key steps.
Abstract: A few bicyclic hybrid sugar molecules comprising of oxa-aza, oxa-oxa, and oxa-carbasugar fused skeletons were designed and synthesized from C-2 acetoxyglucal involving Ferrier rearrangement, Grignard addition, and ring-closing metathesis as key steps. The inhibitory activities of the synthesized molecules were tested against commercially available enzymes, which revealed the sugar–piperidine and sugar–pyran hybrids as potent and selective inhibitors.
TL;DR: In this paper, the Ferrier rearrangement was used to obtain compound (Ia) by using the acetimidate method and compound (i.e., Ia) was obtained by using Ferrier re-arrangement.
Abstract: Compound (Ia) is obtained by using the acetimidate method and compound (Ib) by using the Ferrier rearrangement.
TL;DR: An efficient protocol for the Lewis-acid promoted synthesis of 2,3-unsaturated O- and S-glycosides from glucanes and achiral, as well as chiral primary and secondary alcohols and thioles is presented in this article.
Abstract: An efficient protocol for the Lewis-acid promoted synthesis of 2,3-unsaturated O- and S-glycosides from glucanes and achiral, as well as chiral primary and secondary alcohols and thioles is presented.