The influence of electronic factors on palladium-mediated cycloisomerization: a systematic investigation of competitive 5-exo-dig versus 6-endo-dig cyclizations of sugar alkynols

Ramana, Chepuri V.; Induvadana, Boddeti; Srinivas, Burgula; Kommagalla, Yadagiri; Deshmukh, M. N.; Gonnade, Rajesh G.

doi:10.1016/j.tet.2007.10.072

Cited by 45 publications

(7 citation statements)

References 66 publications

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“…Sialylation reactions with 5-N,7-O-carbonyl-protected sialyl donors show β-selectivity with nitrile solvent (MeCN) assistance (Tanaka, et al, 2008a) Sugar alkynols TOF Investigation of competitive 5-exo-dig versus 6-endodig cyclizations (Ramana, et al, 2008) Triazole-linked Cdisaccharide TOF Validation of the copper(I)-catalyzed azide-alkyne coupling in ionic liquids (Marra, et al, 2008a) Various TOF, ESI Use of whole cellular preparations with a saccharide primer to produce libraries of oligosaccharides Various TOF (DHB), PSD Preparation of saccharide primers for above method 1 Format (not all items present): MALDI method (matrix). ''MALDI'' used when instrument not specified.…”

Section: R-tof (Dhb)mentioning

confidence: 99%

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

Harvey

2011

Mass Spectrometry Reviews

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This review is the fifth update of the original review, published in 1999, on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2008. The first section of the review covers fundamental studies, fragmentation of carbohydrate ions, use of derivatives and new software developments for analysis of carbohydrate spectra. Among newer areas of method development are glycan arrays, MALDI imaging and the use of ion mobility spectrometry. The second section of the review discusses applications of MALDI MS to the analysis of different types of carbohydrate. Specific compound classes that are covered include carbohydrate polymers from plants, N- and O-linked glycans from glycoproteins, biopharmaceuticals, glycated proteins, glycolipids, glycosides and various other natural products. There is a short section on the use of MALDI mass spectrometry for the study of enzymes involved in glycan processing and a section on the use of MALDI MS to monitor products of the chemical synthesis of carbohydrates with emphasis on carbohydrate-protein complexes and glycodendrimers. Corresponding analyses by electrospray ionization now appear to outnumber those performed by MALDI and the amount of literature makes a comprehensive review on this technique impractical. However, most of the work relating to sample preparation and glycan synthesis is equally relevant to electrospray and, consequently, those proposing analyses by electrospray should also find material in this review of interest.

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Section: R-tof (Dhb)mentioning

confidence: 99%

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

Harvey

2011

Mass Spectrometry Reviews

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“…In contrast to the previous work of Gevorgyan7b on the cyclization of o ‐alkynylbiphenyls, which proceeds with a cis ‐selectivity, our study on the cyclization of aromatic enynes 1 showed that the reaction formally occurred with a trans ‐selectivity. On the basis of the stereochemistry of compounds 3 formed (Table 2) and the literature reports,8,16a it seems that the formation of 3 may be rationalized via an electrophilic cyclization of aromatic enynes 1 (Scheme…”

Section: Resultsmentioning

confidence: 81%

Gold versus Palladium: A Regioselective Cycloisomerization of Aromatic Enynes

et al. 2013

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Aromatic enynes can be transformed into arylnaphthalenes or benzofulvenes depending on the reaction conditions. Under gold(I) catalysis, exclusive or major 6-endo-dig cyclization took place leading to arylnaphthalenes. However, a catalytic system based on palladium iodide/1,3-bis(diphenylphosphino)propane, in the presence of cesium carbonate as a base was necessary to furnish exclusively 5-exo-dig cycli-zation pattern, regardless of the electronic effects of the substituents. In the latter transformation, a mechanistic study (kinetic isotopic effect, density functional theory) involving a C À H activation is suggested for the exclusive formation of benzofulvenes.

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“…One key issue for cycloisomerization of γ - hydroxyalkyne is the mode of cyclization: 5- exo-dig versus 6- endo-dig . The systematic investigation by Ramana et al. revealed that the regioselectivity in general was influenced by the electronic nature of the alkyne substituents.…”

Section: General Strategies Toward 68-dobcosmentioning

confidence: 99%

Synthetic Approaches To Construct the 6,8-DOBCO Framework in Natural Products

Zhang

Tong

2016

J. Org. Chem.

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6,8-Dioxabicyclo[3.2.1]octane skeleton (6,8-DOBCO) is a very common structural motif in many biologically active natural products. This synopsis surveys various approaches used to access the 6,8-DOBCO framework present in natural products and summarizes total syntheses of 6,8-DOBCO-containing psoracorylifol B, ent-psoracorylifol C, didemniserinolipid B, and attenol B from our laboratory and others.

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The influence of electronic factors on palladium-mediated cycloisomerization: a systematic investigation of competitive 5-exo-dig versus 6-endo-dig cyclizations of sugar alkynols

Cited by 45 publications

References 66 publications

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

Gold versus Palladium: A Regioselective Cycloisomerization of Aromatic Enynes

Synthetic Approaches To Construct the 6,8-DOBCO Framework in Natural Products

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