ライフサイエンスコーパス: Claisen

1 Claisen condensation, the key step in constructing the p

2 Claisen rearrangement transition states are also highly

3 A Claisen-like rearrangement occurs in the case where ally

4 d via two efficient through processes: (1) a Claisen rearrangement followed by a Ru(VIII)-catalyzed o

5 e synthase, an enzyme which catalyzes both a Claisen condensation and thioester hydrolysis reaction.

6 a link to the indole core is introduced by a Claisen rearrangement from the allylated phenol moiety o

7 a Chan-Lam-type allyloxylation followed by a Claisen rearrangement.

8 er-accelerated catalytic carboalumination, a Claisen rearrangement, and a nucleophilic carbonyl addit

9 dentified, purified, and shown to catalyze a Claisen-type condensation between long chain acyl-CoA su

10 nclude a Ru-catalyzed [5+2] cycloaddition, a Claisen rearrangement, and a ring expansion to construct

11 beta-Ketonitriles derived from a Claisen condensation of benzoate esters with alkyl- or p

12 This allylic alcohol is then utilized in a Claisen rearrangement under Johnson's conditions to intr

13 ond cleavage and C1---C9 bond formation in a Claisen rearrangement.

14 tudy of competitive substituent effects in a Claisen-Schmidt reaction, interfacial effects have been

15 The key steps involve a Claisen rearrangement to set up a 4-substituted-3-methyl

16 These were the result of a Claisen condensation (or Knoevenagel type of reaction) o

17 [Chemical reaction: see text] A Claisen rearrangement/iodolactamization sequence startin

18 The latter, when heated, undergo a Claisen rearrangement and form gamma,delta-unsaturated a

19 tive conformation to spontaneously undergo a Claisen rearrangement.

20 dium-catalyzed vinyl transfer coupled with a Claisen reaction was used to produce the aldehyde requir

21 activation parameters are consistent with a Claisen rearrangement as the rate-limiting step.

22 tion of cyclic carbonate 90 in tandem with a Claisen rearrangement that generates the octenalactone p

23 The carbanion-accelerated Claisen rearrangement has been extended to include phosp

24 phosphorus-stabilized, carbanion-accelerated Claisen rearrangements proceed rapidly at room temperatu

25 the strategy is a tandem Claisen/Diels-Alder/Claisen rearrangement of a suitably substituted xanthone

26 An enantioselective alkoxylation/Claisen rearrangement reaction was achieved by a strateg

27 Key steps include the O-allylation/Claisen rearrangement of spirolactone systems, which are

28 earrangement known as a 3-aza-Cope (or amino-Claisen) reaction.

29 In metal-dependent aldol and Claisen reactions, acidic residues often function either

30 lic isomerizations, allylic alkylations, and Claisen rearrangements.

31 esized through Willimison etherification and Claisen-Schmidt condensation.

32 Benzothiazole formation and Claisen rearrangement involve the cleavage of S-S and C-

33 rbase reagent was tested in Knoevenagel- and Claisen-Schmidt-type condensations and showed conversion

34 relative positions of the bis-pericyclic and Claisen rearrangement transition states may control peri

35 diastereoselective examples of archetypical Claisen rearrangements.

36 atalysts have been designed for the aromatic Claisen rearrangement of a 1,1-dimethylallyl coumarin.

37 The aromatic Claisen rearrangements of allyl p-R-phenyl ethers (R = C

38 lyase homologs that have been known only as "Claisen condensation" enzymes so far.

39 The catalytic asymmetric Claisen rearrangement of a Gosteli-type allyl vinyl ethe

40 ported relying on a key efficient asymmetric Claisen rearrangement, triggered by electrophilic activa

41 Using an aza-Claisen rearrangement as the key step, 7-prenylindole ha

42 Although the aromatic aza-Claisen rearrangement is a general strategy for accessin

43 ssentially constitutes a Pd(0)-catalyzed aza-Claisen rearrangement of N-allyl ynamides, which can als

44 Both routes utilized an efficient aza-Claisen rearrangement to establish the absolute stereoch

45 d acid catalyzed enantioselective indole aza-Claisen rearrangement for the synthesis of chiral 3-amin

46 stigations into Pd-catalyzed and thermal aza-Claisen-carbocyclizations of N-allyl ynamides to prepare

47 onyl shift was made when examining these aza-Claisen rearrangements thermally.

48 domain of the molecule involved a biomimetic Claisen/Diels-Alder cascade, whereas the novel spiroxala

49 xybutyronitrile and the respective esters by Claisen condensation and subsequent Paal-Knorr pyrrole s

50 p, allylation of the 5-hydroxyl, followed by Claisen rearrangement under microwave conditions with co

51 ether 23 by Petasis olefination, followed by Claisen rearrangement.

52 Highly enantioselective catalytic Claisen rearrangements of ester-substituted allyl vinyl

53 roplets is demonstrated for a base-catalyzed Claisen-Schmidt condensation, hydrazone formation from p

54 Indeed, upon Cfa7-catalyzed Claisen condensation between enzyme-bound malonate and a

55 The N-heterocyclic carbene (NHC)-catalyzed Claisen rearrangement of hybrid Ireland-Coates structure

56 ts were discovered as superior in catalyzing Claisen rearrangements of allyloxy- or proparyloxy-subst

57 Unlike in the classical Claisen condensation, however, the VAT-Claisen reaction

58 In the competing Claisen rearrangement, a very large 18O isotope effect a

59 roups, by a novel tandem double condensation/Claisen rearrangement, a gold(I)-catalyzed alkyne hydroa

60 assisted tandem oxyanionic 5-exo cyclization/Claisen rearrangement sequence.

61 t with OleA catalyzing a non-decarboxylative Claisen condensation reaction in the first step of the o

62 on- and energy-efficient non-decarboxylative Claisen condensation reactions and subsequent beta-reduc

63 significantly more reactive toward 1,3-diaza-Claisen rearrangements than isoquinuclidene 2.

64 erionic intermediates that undergo 1,3-diaza-Claisen rearrangements to afford highly substituted urea

65 2 decreases the reactivity toward 1,3-diaza-Claisen rearrangements, while the exodiastereomers 3b an

66 cumulenes are more reactive toward 1,3-diaza-Claisen rearrangements.

67 Metal-catalyzed, double Claisen rearrangement of a bis-allyloxyflavone has been

68 other methods for catalytic enantioselective Claisen rearrangements have not provided a satisfactory

69 t was combined with an Ireland ester enolate Claisen rearrangement.

70 lytic, enantioselective Meerwein-Eschenmoser Claisen rearrangement has been achieved.

71 y crossover observed between the Eschenmoser-Claisen rearrangement and the thio-Claisen rearrangement

72 de, and diisopropylamine, via an ortho ester-Claisen rearrangement from a propargylic alcohol, or via

73 ain, and the other to prephenate by a facile Claisen rearrangement.

74 c triad and its role in catalyzing the final Claisen-type cyclization to the aflatoxin precursor, nor

75 ne were determined as the rate constants for Claisen-type addition of glycine to 1 where deprotonatio

76 Formal Claisen rearrangement gives alpha-benzoyloxyazo compound

77 A sequential allyl vinyl ether formation-Claisen rearrangement process catalyzed by a palladium(I

78 allylic alkoxides gave products arising from Claisen rearrangement, providing access to keto-alkenes

79 d its recently established synthetic role in Claisen/Dieckmann cyclization and product release.

80 S subsequently catalyzes dual intramolecular Claisen and aldol condensations of this linear intermedi

81 was obtained by a similar strategy involving Claisen rearrangement to transfer an allyl group from th

82 gent approach featuring (1) a double Ireland Claisen rearrangement to establish key core bonds with c

83 The key step is a tandem Ireland Claisen/Cope rearrangement sequence, wherein the Ireland

84 rearrangement sequence, wherein the Ireland Claisen rearrangement effects ring contraction to a stra

85 dienes via sequential N-alkylation, Ireland-Claisen ester enolate rearrangement and esterification.

86 as synthesized through the use of an Ireland-Claisen [3,3]-sigmatropic rearrangement.

87 roduct was then obtained by using an Ireland-Claisen ring contraction of 37.

88 epi-basiliolide C are achieved by an Ireland-Claisen/Diels-Alder cascade.

89 tudies of the aldol condensation and Ireland-Claisen rearrangement of the resulting Et 3N-solvated en

90 zes on the highly diastereoselective Ireland-Claisen rearrangement of an acyclic alpha-branched allyl

91 A one-pot difluorocyclopropenation/Ireland-Claisen rearrangement sequence applied to readily availa

92 ion, substrate-directed epoxidation, Ireland-Claisen rearrangement, and diastereotopic group selectiv

93 An initial Ireland-Claisen rearrangement produced the benzannulated enyne-a

94 Last, the tandem metathesis/Ireland-Claisen was utilized to access 4-substituted-3,5-cyclohe

95 A novel Ireland-Claisen approach to the putative structure of eupomatilo

96 thetic sequence involving the use of Ireland-Claisen rearrangement of propargylic acetates to form th

97 s to allyl fumarates with subsequent Ireland-Claisen rearrangement has been accomplished yielding sub

98 The tandem, sequential use of the Ireland-Claisen rearrangement also proved suitable for chirality

99 The Ireland-Claisen rearrangement is effectively utilized to establi

100 The Ireland-Claisen rearrangement is the central step in the synthes

101 The Ireland-Claisen rearrangement of the bis-allylic esters occurred

102 The Ireland-Claisen rearrangement proceeds with high diastereoselect

103 In the case of cyclodienes, the Ireland-Claisen rearrangement produced s-trans locked dienes whi

104 marked (20-fold) acceleration of the Ireland-Claisen rearrangement with evidence of autocatalysis.

105 The Ireland-Claisen was conducted across both acyclic and cyclic die

106 This Ireland-Claisen rearrangement delivered approximate 1:1 mixtures

107 ction and chirality transfer through Ireland-Claisen rearrangement as key steps.

108 tive [2,3]-Wittig-oxy-Cope and isomerization-Claisen rearrangements.

109 readily obtained using olefin isomerization-Claisen rearrangement (ICR) reactions to prepare the key

110 iversity available from olefin isomerization-Claisen rearrangement (ICR) reactions.

111 A one-pot isomerization-Claisen protocol has been developed for the synthesis of

112 logenation of a simple alkene, and a Johnson-Claisen rearrangement that generates a quaternary carbon

113 A novel benzyl fluoride Michael-Claisen reaction sequence was developed to construct the

114 repared by a convergent, single-step Michael-Claisen condensation of AB precursor 1 or 2 with D-ring

115 ations include a diastereoselective modified Claisen condensation, a chemo- and diastereoselective re

116 conjugation proceeds by a nondecarboxylative Claisen condensation.

117 ong the reaction coordinate for this type of Claisen enzyme.

118 thways followed by either tautomerization or Claisen rearrangement.

119 urs rather than the stepwise Michael-type or Claisen-type pathways.

120 etone 16 has been prepared by using an oxaza-Claisen rearrangement, followed by nitrogen deprotection

121 st energy pathway (cation-accelerated oxonia Claisen rearrangement) originates from the second most s

122 quent reactions leading to anomalous phospha-Claisen products were found.

123 These subsequently undergo phospha-Claisen type rearrangement reactions to give the respect

124 zyloxy group and, apparently, follow a photo-Claisen-type mechanism.

125 ), in combination with photo-Fries and photo-Claisen-type reactions of 1-naphthyl (R)-2-phenylpropano

126 The regio- and stereochemistries of photo-Claisen reactions of 1-naphthyl (R)-1-phenylethyl ether

127 In hexane at 23 degrees C, the photo-Claisen products from irradiations of (R)-2 retain up to

128 ic acid residue (Glu117beta) likely promotes Claisen condensation by acting as the catalytic base.

129 The propargyl Claisen rearrangement is a known protocol to gain access

130 t to catalyze the first elongation reaction (Claisen condensation) of type II fatty acid synthesis in

131 anic reactions, namely Diels-Alder reaction, Claisen rearrangement, and Cope-type hydroamination.

132 is stereochemically complementary to related Claisen rearrangement reactions--processes that typicall

133 ngle ambimodal transition state, and a retro-Claisen rearrangement.

134 ic end product via the (SAM-dependent) retro-Claisen rearrangement catalysed by LepI.

135 he product of the asymmetric enzymatic retro-Claisen reaction [(S)-3-oxocyclohexyl]acetic acid.

136 les with allylic alcohols using facile retro-Claisen cleavage to form reactive intermediates in situ.

137 -catalyzed tandem Diels-Alder reaction/retro-Claisen rearrangement.

138 ketone pronucleophile, undergo in situ retro-Claisen activation to generate an allylic acetate and a

139 eeds initially and is followed by the A-ring Claisen reaction.

140 his reaction cascade suggest that the C-ring Claisen/Diels-Alder rearrangement proceeds initially and

141 doxal-glycine iminium ion to form the second Claisen-type adduct 3 as the major reaction product.

142 C) hybrids were synthesized via a sequential Claisen-Schmidt-Knoevenagel-Heck approach and evaluated

143 )-catalyzed olefin isomerization and in situ Claisen rearrangement to afford stereodefined beta-boryl

144 th the carbonyl carbon of 1 to form a stable Claisen-type adduct.

145 ction with styryl bromide via O-styrylation, Claisen rearrangement, ene reaction, and O-alkylation oc

146 yl group to a carboxylic acid and subsequent Claisen condensation with acetyl-CoA.

147 onate 46, methylenation of 46 and subsequent Claisen rearrangement of the corresponding alkenyl-subst

148 Central to the strategy is a tandem Claisen/Diels-Alder/Claisen rearrangement of a suitably

149 c ketone 33 was prepared by sequential Tebbe-Claisen rearrangement of lactones 29 and 30, which origi

150 The Claisen reaction products are elaborated to the chiral S

151 The Claisen rearrangements of chorismate (CHOR) in water and

152 urface by shifting the cycloaddition and the Claisen rearrangement transition states in opposite dire

153 r Diels-Alder reaction, and the Cope and the Claisen rearrangements) have been characterized.

154 addition transition state is followed by the Claisen rearrangement transition state.

155 etoacyl ACP synthase I mtKasA, catalyzes the Claisen-type condensation reaction responsible for fatty

156 oA lyase, a well-known enzyme catalyzing the Claisen condensation of acetyl-CoA with glyoxylate and y

157 New insight into solvent effects for the Claisen rearrangement is presented herein, and a QM/MM a

158 in highly enantioselective catalysts for the Claisen rearrangement of allyloxy- and propargyloxy-indo

159 by the chorismate mutase (CM) enzyme for the Claisen rearrangement of chorismate to prephenate has be

160 he transition state, were calculated for the Claisen rearrangement of chorismate to prephenate in six

161 uch like those observed traditionally in the Claisen condensation.

162 irst examples of asymmetric induction in the Claisen rearrangement with chiral, phosphorus, anion-sta

163 d, and together they enhance the rate of the Claisen rearrangement by a factor of 58 over the backgro

164 Solvent effects on the rate of the Claisen rearrangement of chorismate to prephenate have b

165 eterocyclic carbene catalyzed variant of the Claisen rearrangement.

166 effects on the stereochemical outcome of the Claisen rearrangements have been examined.

167 key step of the first approach relies on the Claisen rearrangement of glucal 18 to provide ester 20a.

168 ole-substituted guanidinium ions promote the Claisen rearrangement of O-allyl alpha-ketoesters and in

169 Thin film formats are used to study the Claisen-Schmidt base-catalyzed condensation of 6-hydroxy

170 on of the methyl group of AcCoA prior to the Claisen condensation to give homocitrylCoA.

171 ant allyl ethers were subjected to a thermal Claisen rearrangement to give the corresponding methyl 7

172 ic iridium(I) catalyst followed by a thermal Claisen rearrangement to provide the allylsilanes in exc

173 -gamma-lactone derivatives using the thermal Claisen rearrangement of the corresponding 3-O- and 2-O-

174 anion formation strategy for asymmetric thio-Claisen rearrangement are documented.

175 mary of our most recent study using the thio-Claisen rearrangement for the synthesis of anti-beta-fun

176 chenmoser-Claisen rearrangement and the thio-Claisen rearrangement is proposed.

177 For the thiono-Claisen rearrangement, a notable structure-reactivity re

178 3,3]-sigmatropic rearrangement of the thiono-Claisen variety that is among the fastest sigmatropic re

179 chain extension by two carbon atoms through Claisen condensation with malonyl-acyl carrier protein.

180 l-2-propenone (PA-1) was synthesized through Claisen-Schmidt condensation between acetyl pyrene and s

181 e PKSs (NR-PKSs) has been shown to extend to Claisen cyclase (CLC) chemistry by catalyzing C-C ring c

182 or Suzuki cross-coupling provides a route to Claisen adducts previously inaccessible from the ICR met

183 aldehyde with an o-hydroxyacetophenone under Claisen-Schmidt conditions afforded a chalcone that was

184 ituted beta-diketones were synthesized under Claisen-Schmidt-type condensation conditions.

185 Specifically, the unimolecular Claisen rearrangement of allyl p-nitrophenyl ether (ApNE

186 been achieved with its heteroatom variants (Claisen, aza-Cope, and so on).

187 sical Claisen condensation, however, the VAT-Claisen reaction described herein is rendered irreversib

188 d enantioselective variants of the venerable Claisen rearrangement remain relatively rare.

189 o the intramolecular delivery of ring E (via Claisen rearrangement, Heck-type cyclization, or radical

190 e-tethered chromanone/coumarin scaffolds via Claisen rearrangement using a solid state melt reaction

191 or 2 is quite rapid at -78 degrees C, while Claisen cyclization of the enolate produced is rate-dete

192 The data are consistent with Claisen condensation from KS to the ACP carrier site bei