ライフサイエンスコーパス: Bronsted base

1 on in concert with proton transfer to a weak Bronsted base.

2 under neutral conditions in the absence of a Bronsted base.

3 ring a tertiary amine that may function as a Bronsted base.

4 promoter and the other performs as a chiral Bronsted base.

5 pend on divalent ions or the identity of the Bronsted base.

6 he ability of molecular sieves to serve as a Bronsted base.

7 his proton-transfer reaction is catalyzed by Bronsted bases.

8 of N-protonated proline methyl ester by the Bronsted base 3-quinuclidinone in water, and it is not c

9 lysis of LiCl (acting as a Lewis acid) and a Bronsted base (a primary or, in selected cases, a second

10 A Bronsted base activation mode for oxidative, Pd(II)/sulf

11 w that the catalyst acts simultaneously as a Bronsted base and an acid catalyst, and the mechanism is

12 tivity (PA) can be adjusted by the choice of Bronsted base and Bronsted acid used in their formation.

13 way with catalysis by the combined action of Bronsted bases and Zn(2+).

14 k1(f)), accounts for the important role of a Bronsted base, and mimics the experimental behavior.

15 The Bronsted base appears to be water or hydroxide ion depen

16 of thiol anions rather than oxygen anions as Bronsted bases at this putative nonpolar enzyme active s

17 presented here based on chiral bifunctional Bronsted base (BB) catalysis and the use of alpha'-oxy e

18 merization and probably acts as a Lewis acid-Bronsted base bifunctional site.

19 n in a series of polymers, including polymer Bronsted bases blended with organic acid proton donors.

20 gh efficiency and practicality, via a chiral Bronsted base-catalysed asymmetric Mannich-type reaction

21 h n-butyllithium, the open analogue exhibits Bronsted base catalysis that cannot be accomplished by t

22 s reported under palladium(II)/bis-sulfoxide/Bronsted base catalysis.

23 A bifunctional Bronsted base catalyst bearing a squaramide with an atta

24 ghly effective new class of enantioselective Bronsted base catalysts.

25 Glu(161) is the Bronsted base catalytically promoting the thioester hydr

26 It is based on a Bronsted base catalyzed cascade reactivity between beta,

27 Specifically, a Bronsted base catalyzed conjugate addition of substitute

28 alyzed by a sterically frustrated Lewis acid/Bronsted base complex is disclosed.

29 yzed by a sterically "frustrated" Lewis acid/Bronsted base complex is disclosed.

30 tioning of the chiral Lewis acid and achiral Bronsted base components gives rise to in situ enolate g

31 ooperative functioning of the Lewis acid and Bronsted base components gives rise to in situ enolate g

32 reactivity of the individual Lewis acid and Bronsted base components of the catalyst and established

33 ar, strongly basic, and tunable bifunctional Bronsted base/H-bond-donor organocatalysts are reported.

34 /phosphine combination or in the presence of Bronsted bases has been explored.

35 Cinchona alkaloid-derived organocatalysts as Bronsted bases have been examined for this asymmetric cy

36 In the absence of an effective Bronsted base, however, slow deprotonation of this adduc

37 ing step, and carbonate anion serving as the Bronsted base in that acyl-transfer step.

38 from the presence or absence of an effective Bronsted base in the reaction.

39 atalyst(s) in Lewis-acid (LA) and Lewis-acid/Bronsted-base (LA/BB) catalyzed reactions.

40 hosphines performed as effective cooperative Bronsted base/Lewis acid catalysts in the asymmetric ald

41 Preliminary data support a Bronsted base mechanism with the free carbene.

42 If stoichiometric Bronsted base (NaOAc, Na2CO3) is added to the latter rea

43 Bronsted bases of widely varying strength are shown to d

44 catalytic and could serve as a Lewis acid, a Bronsted base, or both to facilitate deprotonation of th

45 omoted by a sterically frustrated Lewis acid/Bronsted base pair, which is proposed to operate coopera

46 phosphodiester bond is de-protonated by two Bronsted bases, probably the ionised forms of aspartate

47 Most asymmetric phase transfer reactions are Bronsted base reactions, and the inorganic bases used gr

48 mplexation of benzyl alcohol (BnOH) with the Bronsted base sites on Al2O3, which reduces its oxidatio

49 In the presence of a Bronsted base such as triethylamine or acetate, the kine

50 scope over the use of silanols activated by Bronsted bases such as NaOt-Bu.

51 r 149 is the same as the kinetic pKa for the Bronsted base that facilitates hydride transfer to NAD+.

52 2 is a strong Bronsted base that forms frustrated Lewis pairs (FLPs) w

53 Adding a Bronsted base to (PNP)Nb horizontal lineCH2(OAr)(OTf) al

54 ssible ligand to the first Mn), (2) act as a Bronsted base to accelerate proton release during format

55 , representing the first report of a neutral Bronsted base to catalyze such reactions.

56 ase A2, histidine-34 probably functions as a Bronsted base to deprotonate the attacking water.

57 rotecting group of the aminoalkene acts as a Bronsted base to remove free protons from the catalytic

58 unreactive toward silica in the absence of a Bronsted base, we find that it can be grafted even at ro

59 that of en (i.e., Sn(9)(4-) is a very strong Bronsted base with a pK(b) comparable to that of the NH(

60 pair" mechanism in which the solvent, a weak Bronsted base yet moderately strong donor, plays a pivot