ライフサイエンスコーパス: oxonium

1 Protonation of these species by the oxonium acid [H(OEt(2))(2)](+)[BAr'(4)](-) at low temper

2 oss of positive charge due to destruction of oxonium and pyridine, possibly caused the reduced phosph

3 derivative 12 is O/C diprotonated to give an oxonium-annulenium dication.

4 A concerted 1,2-hydride shift/oxonium formation, followed by elimination, leads to for

5 improved by enrichment method, nanoLC-MS and oxonium glycan ions.

6 rboxylic and phenolic groups, a reduction of oxonium groups and the transformation of pyridine to pyr

7 of a stabilized carbocation from an allylic oxonium intermediate and subsequent trapping by a chiral

8 ations on the O-methyl-2,3-dimethyl-2-butene oxonium ion along with transition states and intermediat

9 th the isomerization of the O-methylethylene oxonium ion and its tetramethyl-substituted analogue hav

10 These oxonium ion Bronsted acids are convenient reagents for t

11 thase in which an SN1-like reaction produces oxonium ion character at C-1 of PRPP which undergoes an

12 The hydride reduction of the intermediate oxonium ion EtO(SiEt(3))(2)(+), 9, occurs via attack by

13 urations of the substrates evidently control oxonium ion formation and their subsequent preferred mod

14 se from a bromonium ion induced transannular oxonium ion formation-fragmentation could also be isolat

15 Bromonium ion induced transannular oxonium ion formation-fragmentation gave the macrocyclic

16 by a face-selective chloronium ion initiated oxonium ion formation-fragmentation process followed by

17 ent exploration of their putative biomimetic oxonium ion formation-fragmentations reactions revealed

18 s includes proton transfer reactions through oxonium ion formation.

19 systems, and these suffer reduction prior to oxonium ion formation.

20 The putative oxonium ion intermediate 17 formed by an intramolecular

21 The oxonium ion intermediates are generated through Lewis ac

22 in situ generation of benzhydryl cation and oxonium ion intermediates from activated alkyl halides.

23 C5' substituent shields the beta-face of the oxonium ion involved in the coupling reaction while the

24 Oxatriquinane, a fused, tricyclic alkyl oxonium ion of unprecented stability, was synthesized in

25 lar modeling, in vitro enzymatic assays, and oxonium ion patterns, we propose that the observed O-lin

26 opening as compared to the O-methylethylene oxonium ion species, leading to a lower probability of i

27 o result from the ring-opening of a bicyclic oxonium ion that follows the nucleophilic capture by the

28 nsely substituted 4-alkoxy quinolines via an oxonium ion triggered alkyne carboamination sequence inv

29 e neighboring imido group, and the resulting oxonium ion undergoes subsequent deprotonation to produc

30 at the oxygen atom for the O-methylethylene oxonium ion, 15.7 kcal/mol, agrees well with the experim

31 POCOP)Ir(H)(2) (5) and diethyl(triethylsilyl)oxonium ion, [Et(3)SiOEt(2)](+)[B(C(6)F(5))(4)](-) (7),

32 owever, addition of a silyl enol ether to an oxonium ion, followed by a one-pot debenzylation/spiroke

33 ddition of the alkene to the aryl 2-oxadiene oxonium ion, followed by an intramolecular aromatic subs

34 constructed via reductive cyclization of the oxonium ion, or oxy-Michael cyclization.

35 ttack of the nucleophile on the intermediate oxonium ion.

36 These oxonium-ion-containing spectra were then compared with t

37 The GIG tool extracts precursor masses, oxonium ions and glycan fragments from tandem (liquid ch

38 glycopeptides were selected by using glycan oxonium ions as signature ions for glycopeptide spectra.

39 In addition, detection of the oxonium ions enabled unambiguous differentiation of glyc

40 the intermediacy of 1-oxabicyclo[3.1.0]hexyl oxonium ions following participation by the pyranoside r

41 tween glycan structures and the intensity of oxonium ions in the spectra of glycopeptides and utilize

42 lling of oxatriquinane alongside other alkyl oxonium ions indicated that the electronic consequences

43 witching for the detection of characteristic oxonium ions of saccharides.

44 Oxonium ions representing the distal subunit were observ

45 Oxatriquinanes are fused, tricyclic oxonium ions that are known to have exceptional stabilit

46 generates mono- or disaccharide ions called oxonium ions that carry information about the structure

47 Protein Prospector can use these diagnostic oxonium ions to find glycopeptides, by showing that a we

48 opeptides using the spectral features of the oxonium ions using verification spectral set.

49 Oxatriquinanes are tricyclic oxonium ions which are known to possess remarkable solvo

50 s of the precursor masses and characteristic oxonium ions.

51 st mass analyzer sufficient to form abundant oxonium ions.

52 arlier reports concerning crotylsilations of oxonium ions.

53 ETD)-MS(2) upon detection of glycan-specific oxonium is one of the better approaches in current LC-MS

54 ochemical conditions with a TMSOTf-catalyzed oxonium-mediated cyclization gave general access to pyrr

55 ormed ammonium (pK(CD(2))(Cl(2)) 5.7-8.2) or oxonium (pK(CD(2))(Cl(2)) -4.7-1.6) regulates the proton

56 hieno[3,2-c]pyran skeleton predominantly via oxonium-Prins cyclization.

57 yloxatriquinane (1), a 3-fold tertiary alkyl oxonium salt, is described.

58 olvolytic stability compared to simple alkyl oxonium salts.

59 ceptional stability compared to simple alkyl oxonium salts.

60 represent the first examples of stable allyl oxonium species.

61 Tris(triphenylphosphinegold) oxonium tetrafluoroborate, [(Ph3PAu)3O]BF4, catalyzes th

62 certain carbophilic metals trigger carbenoid/oxonium type pathway.

63 tative 1,2-group shift within an unsaturated oxonium ylide (Stevens rearrangement) accounts for the o

64 es result in tandem reactions, consisting of oxonium ylide formation followed by [2,3]-sigmatropic re

65 te results in a two-step process, an initial oxonium ylide formation followed by a [2,3]-sigmatropic

66 on with the reactant diazo compound inhibits oxonium ylide formation in copper-catalyzed reactions.

67 s for polyether coordination, intramolecular oxonium ylide formation occurs at the terminal oxygen, f

68 isting of five distinct steps: rhodium-bound oxonium ylide formation, [2,3]-sigmatropic rearrangement

69 Rh(II)-catalyzed oxonium ylide formation-[2,3] sigmatropic rearrangement

70 opropanation, carbon-hydrogen insertion, and oxonium ylide generation are compared from reactions of

71 An oxonium ylide rearrangement formed the trisubstituted te

72 o four carbon atoms in intermediates such as oxonium ylides, carbenes, carbocations, and free radical