ライフサイエンスコーパス: acid catalyst

1 idize alcohols to carbonyl compounds without acid catalyst.

2 choice of auxiliary and the choice of Lewis acid catalyst.

3 [Cu((S,S)-t-Bu-box)](SbF6)2 (1a) as a Lewis acid catalyst.

4 s intermediate presumably requires a general acid catalyst.

5 with benzaldehyde in the presence of a Lewis acid catalyst.

6 s is highly dependent upon the nature of the acid catalyst.

7 ified DNAs to implicate Lys-167 as a general acid catalyst.

8 ained by using an acid-exchange resin as the acid catalyst.

9 the vicinity that can function as a general acid catalyst.

10 a) 6.8) should require no assistance from an acid catalyst.

11 nd R to probe its possible role as a general acid catalyst.

12 role of this active-site serine as a general acid catalyst.

13 lizing a nitrated confined imidodiphosphoric acid catalyst.

14 ished through the use of a chiral phosphoric acid catalyst.

15 ed using a chiral confined imidodiphosphoric acid catalyst.

16 eds without involving the Bronsted and Lewis acid catalyst.

17 d phosphoric acid (VAPOL-PA) as the Bronsted acid catalyst.

18 (4+):acac enol-type complex can act as Lewis acid catalyst.

19 Coking leads to the deactivation of solid acid catalyst.

20 umarins in the presence of a chiral Bronsted acid catalyst.

21 a over an inexpensive titanium dioxide solid acid catalyst.

22 the boronate oxygen by the chiral phosphoric acid catalyst.

23 n is endo-selective in the presence of Lewis acid catalyst.

24 ermediate are presented to the conserved Lys acid catalyst.

25 pyrroline in the presence of a mild Bronsted acid catalyst.

26 steric control upon the addition of a Lewis acid catalyst.

27 with the 2'OH of G8, the implicated general acid catalyst.

28 of a catalytic amount of a chiral phosphoric acid catalyst.

29 was demonstrated using this chiral Bronsted acid catalyst.

30 modified dienophile segments; and different acid catalysts.

31 acids are the kinetically competent Bronsted acid catalysts.

32 y to aid the design of next-generation Lewis-acid catalysts.

33 nto the Bronsted acidity of a range of solid acid catalysts.

34 ds represent an attractive class of Bronsted acid catalysts.

35 y overestimates the computed KIEs for strong acid catalysts.

36 diene 13 in the presence of the chiral Lewis acid catalyst 14 to form 15 (85% yield, 97% ee, >98:2 en

37 iphenylcorrole (TPC) to survey the effect of acid catalyst, acid concentration, ratio of pyrrole to d

38 Solvent, acid catalyst, acid quantity, oxidant, oxidant quantity,

39 A survey of acid catalysts, acid catalyst concentration, DDQ quantit

40 H suggests that Tyr(465) and Tyr(381) act as acid catalysts, activating the epoxide ring and facilita

41 ize the transition state or act as a general acid catalyst after the rate-determining step.

42 NMR data thus indicate that betaPro-1 is the acid catalyst, alphaGlu-52 is a reasonable candidate for

43 Lewis acid catalysts alter the shape of the surface by shiftin

44 imerizing self-assembly between a phosphoric acid catalyst and a carboxylic acid has recently been es

45 action using ferric chloride both as a Lewis acid catalyst and as an oxidant in excellent yields.

46 nucleophile using either a Bronsted or Lewis acid catalyst and that the resulting rearrangement proce

47 vent jointly mediated by a chiral phosphoric acid catalyst and the photoredox catalyst Ir(ppy)2(dtbpy

48 The effects of different amino acid catalysts and substrate substituents on the stereos

49 tionship between the acidities of phosphoric acid catalysts and their reaction activity and selectivi

50 ween anti- and syn-chairs with primary amino acid catalysts and, consequently, the stereoselectivitie

51 er Asp-92 or Asp-72 functions as the general acid catalyst, and that this enzyme undergoes a change i

52 cts simultaneously as a Bronsted base and an acid catalyst, and the mechanism is similar to that of t

53 r the synthesis of benzyne precursors, Lewis acid catalysts, and certain luminophores.

54 ility of the solvent and the strength of the acid catalyst are explored.

55 tions demonstrate that both general base and acid catalysts are required for the formation and stabil

56 Heterogeneous Bronsted acid catalysts are tremendously important in industry, p

57 Chiral acid catalysts are useful for the synthesis of enantioen

58 mically amplified resists (CARs) that employ acid catalysts are widely used throughout the semiconduc

59 drate is found to be an efficient and strong acid catalyst as well as an effective protosolvating med

60 s is presented, covering biocatalysts, Lewis acid catalysts based on boron and metals as well an asso

61 r and alkanol cleavage reactions on Bronsted acid catalysts based on polyoxometalate (POM) clusters a

62 Here, we report using reconfigurable nucleic acid catalyst-based units to build a multipurpose reprog

63 frameworks (MOFs) are known to act as Lewis acid catalysts, but few reports have explored their abil

64 y, and commonly observed reactivity of Lewis acid catalysts cannot be attributed to the eventual form

65 to be catalyst dependent; Lewis and Bronsted acid catalysts caused an ionization/SN1' isomerization t

66 A highly reactive and robust chiral Bronsted acid catalyst, chiral N-triflyl thiophosphoramide, was d

67 sights into the structures of imine/Bronsted acid catalyst complexes are presented on the basis of NM

68 A survey of acid catalysts, acid catalyst concentration, DDQ quantity, and reaction

69 in molecules and two to six attached nucleic acid catalysts (deoxyribozymes), with phosphodiesterase

70 -262 was identified as the authentic general acid catalyst, donating a proton to the leaving group ox

71 xyl group of Tyr108 might serve as a general acid catalyst during substrate turnover.

72 Asp38 serves as a general acid catalyst during the 'reverse kinase' reaction by do

73 C could be prepared via a subset of the mild acid catalysts [Dy(OTf)(3) and Yb(OTf)(3)], and a prepar

74 s was investigated to determine whether mild acid catalysts [Dy(OTf)(3), Yb(OTf)(3), Sc(OTf)(3), and

75 to an oligomerization reactor containing an acid catalyst (e.g., H ZSM-5, Amberlyst-70), which coupl

76 and, to some extent, the nature of the Lewis acid catalyst employed.

77 The bifunctional chiral protic acid catalyst enables these reactions to proceed without

78 While aspartic acid 135 is the acid catalyst for dehydration in the wild-type enzyme, t

79 Tungstated zirconia is a robust solid acid catalyst for light alkane (C(4)-C(8)) isomerization

80 covalent intermediate by acting as a general acid catalyst for loss of the C4 hydroxyl group.

81 is reported using Ni(ClO4)2.6H2O as a Lewis acid catalyst for nucleophilic amine ring-opening cycliz

82 We show that PtI(4) is an effective Lewis acid catalyst for the activation of terminal alkynes for

83 riflic acid is also found to be an effective acid catalyst for the direct synthesis of some electron-

84 h a pK(a) of 6.0 and Tyr-74 may be a general acid catalyst for the elimination step, as we found prev

85 uperacid CF3SO3H is found to be an effective acid catalyst for the Knorr cyclization.

86 luated the efficacies of a series of soluble acid catalysts for an intramolecular Friedel-Crafts addi

87 use of metalloenzyme-like zeolites as Lewis acid catalysts for C-C bond formation reactions has rece

88 oping new highly porous, heterogeneous Lewis acid catalysts for multicomponent reactions, a new mesop

89 arboxylate (DMTC) as the most powerful amino acid catalysts for the reaction of both acyclic and cycl

90 ghput catalyst screening and allowed several acid catalysts for the reaction to be identified.

91 echanism in which H61 and H79 act as general acid catalysts for the stereospecific elimination of the

92 red an important supported metal oxide model acid catalyst, for which structure-property relationship

93 n of the anion in the absence of the general acid catalyst, Glu370(H(+)).

94 In the presence of a diarylborinic acid catalyst, glycosyl methanesulfonates engage in regi

95 ein, the arene core of ortho-iodoarylboronic acid catalysts has been optimized with regards to the el

96 kly coordinating anion, like methanesulfonic acid) catalyst has been declared commercially ready.

97 BINOL-derived phosphoric acid catalysts have been used to achieve the synthesis o

98 Cys(45) and Cys(50), the enzyme contains an acid catalyst, His(456), having a pK(a) of 9.2 that prot

99 ated in the aqueous phase with the use of an acid catalyst (hydrochloric acid or an acidic ion-exchan

100 ution and strongly supports A38 as a general acid catalyst in bond scission.

101 ta/alpha)(7)beta-barrel domain serves as the acid catalyst in both reactions.

102 cyanide in the presence of a palladium Lewis acid catalyst in dichloromethane solvent at room tempera

103 It is shown that CrCl3 is an active Lewis acid catalyst in glucose isomerization to fructose, and

104 ence is the absence of a carboxylate general acid catalyst in RNA triphosphatase.

105 e A plays a major role as an imidazolium ion acid catalyst in the cyclization/cleavage of normal dinu

106 that Tyr-95 does not function as the general acid catalyst in the reaction catalyzed by wild-type PPT

107 oying up to 10 mol % bulky chiral phosphoric acid catalysts in boiling toluene allowed the product ma

108 as effective cooperative Bronsted base/Lewis acid catalysts in the asymmetric aldol reaction of isocy

109 nts delivered by bis(oxazoline)-Cu(II) Lewis acid catalysts in the Diels-Alder reaction of cyclopenta

110 maldehyde and lactams using recyclable solid acid catalyst is described.

111 e use of chiral carboxylic acids as Bronsted acid catalysts is much less developed but has recently g

112 tely 10 kcal/mol when phenol, as the general-acid catalyst, is included in the gas-phase calculations

113 conformation, but, functioning as a Bronsted acid catalyst, it also activates the dienophile toward r

114 dialdehydes with pyrroles in the presence of acid catalysts leads to the formation of a new class of

115 e of d-mannose at the +1 subsite renders the acid catalyst less efficient during the cleavage of the

116 s by a proton juxtaposed at S6 via a general acid catalyst located on the E1 enzyme.

117 The borinic acid catalyst not only influences site-selectivity via a

118 elds with a low loading of a bidentate Lewis acid catalyst of 2 to 5 mol %.

119 Fe(OTf)2 was the Lewis acid catalyst of choice for the formation of dihydroquin

120 tes (IDPis) are extremely effective Bronsted acid catalysts of the hetero-Diels-Alder reaction of a w

121 on were observed when polyvalent anthranilic acid catalysts operating on polyvalent aldehyde substrat

122 catalyst (TFA or BF3.OEt2), concentration of acid catalyst, oxidant quantity, and reaction time on th

123 approach was employed, in which a phosphoric acid catalyst, oxidant, and reductant are present in the

124 ructose, and the combined Lewis and Bronsted acid catalysts perform the isomerization and dehydration

125 of Pro-1 functions as the nucleophile and an acid catalyst polarizes the carbon oxygen bond.

126 Highly active palladium-phosphinous acid catalysts POPd, POPd1, and POPd2 have been employed

127 The chiral Bronsted acid catalyst R-TRIP (3,3'-bis(2,4,6-triisopropylphenyl)

128 e presence of 1 mol % of a chiral phosphoric acid catalyst, reactions reach completion within 10 min

129 th epoxides in the presence of a homogeneous acid catalyst readily delivers the corresponding dioxepi

130 The counteranion of the acid catalyst remains in the reaction site playing an im

131 0.4 for an essential base and a nonessential acid catalyst, respectively, in the active quaternary Mu

132 ure supports the assignment of Asp405 as the acid catalyst responsible for cleavage of the glycosidic

133 In control: A chiral phosphoric acid catalyst significantly enhances or completely overr

134 dic defect sites on oxide surfaces and Lewis acid catalyst sites consisting of grafted calixarene-Ti(

135 tion state, which is stabilized by the Lewis acid catalyst SnCl(4) and by polar solvents.

136 Nanoporous acid catalysts such as zeolites form the backbone of cat

137 havior is displayed by strong solid Bronsted acid catalysts, such as H-mordenite and H-beta.

138 Using a Rh(I)/DPEphos/benzoic acid catalyst system, terminal alkynes react with sulfon

139 Employing palladium-phosphinous acid catalyst [(t-Bu)(2)P(OH)](2)PdCl(2) allows formatio

140 After survey of pyrrolidine-based Bronsted acid catalyst, tetrazole catalyst (3f) was found to be o

141 t of reactant concentration, reactant ratio, acid catalyst (TFA or BF3.OEt2), concentration of acid c

142 nt, was found to be a highly selective Lewis acid catalyst that affects the heteroacylative dimerizat

143 anism where the 2'OH of G8 acts as a general acid catalyst that is held in position through Watson-Cr

144 encode early vertebrate forms of arachidonic acid catalysts that are widely expressed and are regulat

145 F are reacted with ethylene over solid Lewis acid catalysts that do not contain strong Bronsted acids

146 st that Tyr(381) and/or Tyr(465) are general acid catalysts that facilitate epoxide ring opening in t

147 on results obtained for homogeneous Bronsted acid catalysts that span a range of pKa values, we sugge

148 r was unaffected by the presence of water or acid catalysts, thereby ruling out reversible Se-O or be

149 ereas the addition of a mixture of the Lewis acid catalysts Ti(O(i)Pr)4 and BF3 enables the formation

150 may serve directly or via water as a general acid catalyst to aid in 5-iminium cation formation.

151 41, which has been considered as the general acid catalyst to assist departure of the leaving nucleob

152 By using a solid acid catalyst to pretreat a gas stream, we have discover

153 prochiral diesters with a chiral phosphoric acid catalyst to produce highly enantioenriched lactones

154 hypothesis that involves the addition of the acid catalyst to the diene, followed by nucleophilic dis

155 id in the precise positioning of the general acid catalyst to the N3 of the imidazole of AICAR.

156 ing the power of these especially mild Lewis acid catalysts to provide novel asymmetric reactions.

157 the proton transfer from Asp164 (the general acid catalyst) to the inhibitor is not.

158 Interestingly, mutation of Asp135, the acid catalyst, to Asn or Ala alters the mechanism, allow

159 enantioselectivity of the chiral phosphoric acid catalyst used in these reactions.

160 The efficacy of the new boronic acid catalyst was confirmed by its ability to activate p

161 cid (Asp(60)) invoked as a candidate general acid catalyst was dispensable for phosphohydrolase activ

162 e nitrile substrate by the Bronsted or Lewis acid catalyst was found to be responsible for the rate e

163 Identification of the acid catalyst was performed using an alternative substra

164 propyltrimethoxysilane in the presence of an acid catalyst, water, toluene, and a photoinitiator was

165 Chiral Lewis acid catalysts were generated by postsynthesis functiona

166 More specifically, BINAM-derived phosphoric acid catalysts were shown to prevent alkene isomerizatio

167 catalyst and His-144 serving as the general acid catalyst, whereas the side chain of Tyr-142 probabl

168 the betaPro-1), implicating betaPro-1 as the acid catalyst, which may protonate C-2 of the substrate.

169 ular organocatalysts and heterogeneous Lewis acid catalysts, while affording additional recyclability

170 n catalysis, most likely acting as a general acid catalyst with a pK(a) value greater than 10.5.

171 ts in a salt bridge with Asp144 as a general acid catalyst with a pK(a) value of 9.7.