ライフサイエンスコーパス: ring closure

1 high diastereoselectivities (up to 90% trans ring closures).

2 ggest that GpsB, like Pbp2x, mediates septal ring closure.

3 2-formylbenzeneboronates followed by McMurry ring closure.

4 ponsible for the diastereoselectivity of the ring closure.

5 en (H*) from C1 of S-HPP to initiate epoxide ring closure.

6 de reduction, chlorination, and base-induced ring closure.

7 emoselective nitrogen functionalization, and ring closure.

8 h an aldehyde) and Ag(I)- or Hg(II)-mediated ring closure.

9 a-methoxycarbonyl dienone and an iso-Nazarov ring closure.

10 m ion formation, 1,5 H-transfer, followed by ring closure.

11 mellitic triimides via dehydration and imide ring closure.

12 modynamic preference for the hexenyl radical ring closure.

13 on of acetic acid, and a final electrocyclic ring closure.

14 dical, which affords phenantridine (3) after ring closure.

15 an alternative palladium-catalyzed oxidative ring closure.

16 eroxide intermediates followed by hemiacetal ring closure.

17 subunits so as to release the constraint of ring closure.

18 rovide high enantiofacial selectivity in the ring closure.

19 ent with a W-shaped transition structure for ring closure.

20 The reverse occurs in ring closure.

21 c macrocyclization substrate for 49-membered ring closure.

22 Alkyl substitution is required for ring closure.

23 c macrocyclization substrate for 49-membered ring closure.

24 ether to the nitrovinylquinone, followed by ring closure.

25 owed by deprotection and Cu(OAc)(2)-promoted ring closure.

26 nd bicyclomycin to be a direct antagonist of ring closure.

27 h the goal of uncovering basic principles of ring closure.

28 omoting an unusual and disfavored 4-exo-trig ring closure.

29 P are both required to cooperatively promote ring closure.

30 consists of ring opening, bond rotation, and ring closure.

31 wise pathway, namely by 10pi followed by 6pi ring closure.

32 ter-ring pivot joints that articulate during ring closure.

33 ons that fail to acquire mLnp1 undergo rapid ring closure.

34 hydration to occur at all potential sites of ring closure.

35 is described using diphosgene to induce the ring closure.

36 and type II myosins and promotes contractile ring closure.

37 hesis by enantioselective (er = 61:39) 5-exo ring closure.

38 e, which is followed by rapid intramolecular ring closure.

39 these cascades is typically the second (6pi) ring closure.

40 by MCM, promoting both Cdt1 ejection and MCM ring closure.

41 n of AIM44 results in defects in contractile ring closure.

42 t to C5 of L-proline followed by beta-lactam ring closure.

43 ion, alpha-chlorination, and hydride-induced ring closure.

44 (Nu:) ortho to the amine for intramolecular ring closure.

45 red throughout cytokinesis until contractile ring closure.

46 n a rate-determining step (RDS) which is not ring-closure.

47 ration of an oligonucleotide duplex enhances ring-closure.

48 quinone, which is followed by an oxa-Michael ring-closure.

49 atalyzed aminations and Friedel-Crafts-based ring closures.

50 tem, and the defined order of CD, AB, and DE ring closures.

51 ly at the C-atoms of the C=N bonds, by 5-exo ring closures.

52 ate to cleave these C-H bonds and direct the ring closures.

53 es explains the reduced selectivity of these ring closures.

54 -Z alkene isomerization, a 6pi electrocyclic ring closure, a [1,5]-sigmatropic shift of hydrogen, a 6

55 The UV-induced ring closure afforded substantial changes to the electro

56 of light from the P(OEt)3-mediated Mitsunobu ring closure afforded yields of >95%, presumably owing t

57 Ring closure also changes the interface between the stal

58 The energy-releasing, VHF-to-DHA, ring closures also occur in a stepwise manner and are sy

59 ndlin is required to maintain division after ring closure, although its GAP activity is only required

60 27 by a four-step procedure: acid-catalyzed ring closure, amino nitrile formation, introduction of t

61 rough two reaction pathways: (a) 6-endo-trig ring closure and (b) rearrangement of an intermediate me

62 inal step of PQQ formation, which involves a ring closure and an overall eight-electron oxidation of

63 propargylation that is followed by 5-exo-dig ring closure and double-bond isomerization.

64 n of optimal substrates for triazole-forming ring closure and for the course of the reaction to be co

65 Of interest, ring closure and hence the furrow ingression are nonconc

66 ndergoes trans-cis isomerization followed by ring closure and hydrogen migration prior to hydrogen at

67 rocyanine unit leads to an increased rate of ring closure and serves to push the steady-state composi

68 The monocyclic ring closure and the dimer-dimer ring concatenation were

69 r, both the exo/endo-mode selectivity of the ring closure and the E/Z selectivity of the 1,3-dienes w

70 mplete control over the torquoselectivity of ring closure and the regioselectivity of subsequent depr

71 n of inexpensive starting materials, ease of ring-closure and subsequent polymerization makes this an

72 hwarted the final projected C-C bond forming ring closure, and gilbertine could not be prepared by th

73 round the exocyclic C==N bond, electrocyclic ring closure, and loss of N(2) were calculated using ab

74 ibilities using atomic force microscopy, DNA ring closure, and single-molecule force spectroscopy wit

75 ambiguously demonstrated that these specific ring closures are reversible, leading to the major diast

76 (TSs) of 5-endo-dig and 5-endo-trig anionic ring closures are the first unambiguous examples of nonp

77 n-metathesis-derived macrocycles that employ ring closure at the beta-position of key pTyr-mimicking

78 reaction (PSR) involves the condensation and ring closure between a beta-arylethylamine and a carbony

79 step annulation involving an electrochemical ring closure between a furan and a silyl enol ether has

80 Nucleotide binding does not promote ring closure but does cause the particle to constrict in

81 s show that 4 does not undergo electrocyclic ring closure but reacts exclusively by photofragmentatio

82 initiating and maintaining the asymmetry of ring closure but the role of possible asymmetry in the m

83 Deletion of MDM10 inhibits contractile-ring closure, but does not inhibit contractile-ring asse

84 A subsequent deauration step promotes ring closure by 1,7-electrocyclization through an intram

85 astereoselection) followed by 14-membered FG ring closure by macrolactamization (66%).

86 o be an effective and versatile tool for the ring closure by peptide bond formation.

87 riched alpha-hydrazino esters that underwent ring closure by using Ph(3)PAuCl/AgBF(4) as a catalytic

88 yloxyacetic acids adapted for intramolecular ring closures by inclusion of 2-alkenyl, 2-aryl, or 2-ox

89 The final step involved an SN1-type ring closure catalyzed by DDQ to construct the 1,2-dioxe

90 Heating solutions of these salts induces ring closure cleanly and regioselectively via formal "ex

91 oketone and phenylmethanimine, followed by a ring-closure condensation.

92 ple bond reduce the activation energy of the ring closure considerably.

93 Ring closure correlated with the viability and migration

94 We found that the regioselectivity of ring closure depends on the relative configuration of th

95 ions, including halogenation, hydroxylation, ring closure, desaturation and aromatic ring cleavage re

96 ha-D-glucose limits the rate at low pHs, but ring closure does not become rate limiting at pHs up to

97 ransition state results in a torquoselective ring closure (dr up to 15.7:1).

98 is issue, Xue and Sokac show that actomyosin ring closure during Drosophila melanogaster cellularizat

99 tivities (i.e., hydroxylation, desaturation, ring closure, etc.), they all share a common structural

100 Ring closure experiments demonstrated that looping requi

101 rinting, electrophoretic mobility shift, and ring closure experiments suggested that it forms both ge

102 wo-step, one-pot protocol: an intramolecular ring closure followed by a thermally induced dethreading

103 been prepared with high diastereocontrol by ring closure followed by equilibration.

104 with a pent-4-yne type side chain underwent ring closure followed by rearrangement to afford a pyrro

105 This order of ring closures follows their increasing ease of thermal a

106 Ring closure gave the oxazolidinone, and successive depr

107 Intersystem crossing followed by ring closure gives the observed products.

108 epwise Diels-Alder reactions, the subsequent ring closure has unappreciable barriers, in these FHCs t

109 ring opening followed by proton transfer and ring closure have also been explored and suggest that de

110 ition event, followed by an iminium addition ring-closure/hydride migration/alkene isomerization casc

111 ining Lys-110 and Lys-53/Glu-51 catalyze the ring closure (i.e. condensation and decarboxylation) and

112 ry, here we explore the patterns of internal ring closure in the growing membrane in response to asym

113 s that the reaction proceeds via conrotatory ring closure in the triplet excited state.

114 Characterization of ring-closure in single-stranded and in melted duplex oli

115 This work details the complexity of ring-closure in the nucleoside and oligonucleotides and

116 ne, and (iii) one-pot mesylation followed by ring closure induced by a base.

117 tion/cyclization and an Ullmann-type lactone ring closure into the pentacyclic lamellarin skeleton.

118 These studies suggested that the key ring closure involved an initial oxidation of the silyl

119 Mitsunobu activation afforded final ring closure involving the creation of two bonds, which

120 enamine is such that a facile electrocyclic ring closure is ensured, which is corroborated by the ex

121 An unusual preference for endo ring closure is exhibited in contrast to existing exo se

122 The exo mode of ring closure is favored for these 6pi electrocyclization

123 The silver-catalyzed ring closure is highly effective in cyclizing aryl-, alk

124 Thus, cytokinetic ring closure is promoted by moderate levels of both moto

125 An electrocyclic ring closure is the key step of an efficient one-pot met

126 e and fluorescence changes demonstrates that ring-closure is biphasic, leading to the rapid formation

127 employed for light-induced electrocyclic 4pi ring closure leading to bicyclo-beta-lactam photoproduct

128 i(toluene)](+)[B(C(6)F(5))(4)](-), induces a ring closure leading to the cationic four-pi-electron fo

129 ural-abundance NH4OAc buffer, and Paal-Knorr ring closure) leading to the dihydrodipyrrin-acetal.

130 Cu(OAc)(2)-promoted oxidative ring closure leads to dehydro[14]annulenes and dehydro[1

131 s and new polygons, and junction sliding and ring closure leads to polygon loss.

132 de exists in the structural requirements for ring closure may facilitate the development of therapeut

133 Ring closure may serve as a promising label-free and qua

134 In addition, an alternative 1,6-ring closure mechanism via the bisabolyl cation has prev

135 2 which were cyclized to spiro-olefins using ring closure metathesis methodology (Grubbs' catalyst).

136 of zinc catalysts undergo Michael initiated ring closure (MIRC) reactions with gamma,delta-epoxy-alp

137 he rate- and selectivity-determining step is ring closure, not betaine formation as was the case for

138 In no example was ring closure observed to operate.

139 The electrocyclic ring closure occurs in the singlet excited-state for the

140 acid epoxidase (HppE) catalyzes the epoxide ring closure of (S)-HPP to form fosfomycin, a clinically

141 NH) was investigated on the 1,6-transannular ring closure of 1,6-cyclodecadiyne (8a).

142 y stereoselective 6pi-electron electrocyclic ring closure of 1-azatrienes is a key step in formal [3

143 y stereoselective 6pi-electron electrocyclic ring closure of 1-azatrienes.

144 synthesized efficiently via a CuI-catalyzed ring closure of 2-haloaromatic ketones.

145 An electrocyclic ring closure of a 2-azapentadienyl anion generated in si

146 ss of (15)N upon TiCl3-mediated McMurry-type ring closure of a nitro((15)N)hexanone is attributed to

147 Oxidative ring closure of alkyl-substituted 2-hydroxyacetophenone

148 oanilines with cyanamide followed by in situ ring closure of an N-cyanobenzamide intermediate.

149 The reaction is initiated by silver-induced ring closure of beta-chloroamines using the Ag salt of t

150 The ring closure of domino protocol was highly stereoselecti

151 the potential surface for the electrocyclic ring closure of E-7-azahepta-1,2,4,6-tetraene 3 to 1-aza

152 za-proline derivatives has been developed by ring closure of enantioenriched alpha-hydrazino esters b

153 toxyborohydride (STAB-H) and TFA followed by ring closure of intermediate amine 9 to compound 1 in th

154 catalyzes the four-electron oxidative double ring closure of its substrate ACV.

155 dinoproclavaminic acid (DGPC), the oxidative ring closure of proclavaminic acid (PC), and the desatur

156 oxides are directly prepared by nucleophilic ring closure of propargylic alkoxides generated by lithi

157 s been developed via the Lewis acid-mediated ring closure of stilbenyl methanols followed by nucleoph

158 Ring closure of the 1,4-diradical to diphenylcyclobutane

159 Several approaches to the macrocyclic ring closure of the 13-membered ring were investigated,

160 Ring closure of the 2'-hydroxyl group onto a secondary m

161 atriene 39 (paths a1 and a2); and path b via ring closure of the carbene onto the ring nitrogen, yiel

162 e core formation involving an intramolecular ring closure of the carbodiimide-derived phosphazene int

163 After base-mediated ring closure of the chlorohydrin enantiomers, the epoxid

164 he pseudopterosins arises from the selective ring closure of the cis- and trans-amphilectosins.

165 The 13C8 atom is introduced by means of a ring closure of the exocyclic amino groups of a pyrimidi

166 origins of diastereoselection in the second ring closure of the highly diastereoselective double Hec

167 dropyridine, probably because the 6-exo-trig ring closure of the iminyl radical was too slow to compe

168 A consecutive ring closure of the intermediate leads to an ethynyl-sub

169 his unconventional cyclization describes the ring closure of the macrocyclic diterpene casbene.

170 bodiimde and the direction of the subsequent ring closure of the N-acyl hydrazide adduct.

171 719), a method for the late stage pyrimidine ring closure of the nitrogen-protected endo 2-norborneny

172 e limits the rate, and on the alkaline side, ring closure of the open-chain sugar limits the rate.

173 ep in the synthesis of 1 involves 5-exo-trig ring closure of the vinyllithium derived from (Z)-1-iodo

174 pine 6,6-dioxides it has been found that the ring closure of the zwitterion leading to the formation

175 an-3(2H)-one derivative, suggesting that the ring closure of these diols is both chemo- and regiosele

176 Ring closure of these intermediates led to the target, l

177 have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes.

178 Ring closure of vinylogous derivative 12 in the presence

179 Transition metal-catalyzed double ring closures of 1,1-diaryl-2,2-diethynylethylenes yield

180 The absence of this second effect in the ring closures of several divinyl ketones explains the re

181 dicted reversal of stereoselectivity for the ring closures of several silyl substituted azatrienes ha

182 ng from 2-phenylnicotinaldehyde derivatives, ring closures of the derived iminyl radicals onto the ph

183 y and transition states of the electrocyclic ring closures of the resonance-stabilized 1,4-pentadieny

184 The ring closures of these bridged bicyclic trienes are up t

185 this steric clash ensures the subsequent 6pi ring closures of these intermediates are both kineticall

186 and a reversible 6pi-electron electrocyclic ring-closure of 1-oxatrienes.

187 The ring-closure of the aryllithium derived from 2-(o-bromob

188 f short duplexes, altering the dependence of ring closure on chain length in a way that cannot be mim

189 Similarly, ring closure onto a phenyl ring from a benzothiophene-ba

190 By way of contrast, iminyl radical ring closure onto pyridine rings was not observed.

191 intermediate that also engages in 5-exo-trig ring closures onto pendant alkenes prior to the terminat

192 is photo-switchable following the reversible ring closure/opening of the central dithienylethene via

193 gnostic of the preferred mode of conrotatory ring closure operating within equilibrating helical inte

194 logenated ketones followed by intramolecular ring closure or by a copper- or palladium-mediated heter

195 e in septin organization but not contractile ring closure or septum formation.

196 might form directly from 10 by addition and ring closure, or their formation might involve water cat

197 olvement of the alternative biosynthetic 1,6-ring closure pathway.

198 The competing proton transfer or direct ring-closure pathways that are open to the betaine inter

199 By eliminating the quinone, this ring closure prevents comproportionation and the consequ

200 An oxidative DDQ-induced ring-closure process is also possible, generating the co

201 bond, made possible by a controlled radical ring-closure process of the carbene radical intermediate

202 yl-2(1H)-pyrimidin-(thi)ones, a ring-opening/ring-closure process was contributing to the observed ra

203 ic resolution of hydroxyenones followed by a ring-closure process.

204 aining materials via an exclusive 6-endo-dig ring-closure process.

205 Tf)3, CH3CN, 80 degrees C) promotes a double ring-closure process: (i) condensation between the alpha

206 (3)SnH/AIBN produced an analogous mixture of ring-closure products.

207 In some cases the ring closure reaction afforded the isomeric (and readily

208 the active site to favor the intramolecular ring closure reaction and that this reaction may be cata

209 nantioselective intramolecular hydride shift/ring closure reaction is reported.

210 two alkyne units as well as the transannular ring closure reaction of a nonconjugated diyne.

211 by an extremely facile oxa-6pi-electrocyclic ring closure reaction of an ortho-quinone intermediate,

212 The exo/endo selectivity of the ring closure reaction of these substrates was found to b

213 species plays a key role in this unexpected ring closure reaction.

214 roduct merocyanine isomers, as well as their ring-closure reaction back to the spiropyran form.

215 e describe the kinetics and mechanism of the ring-closure reaction in both the nucleoside and oligonu

216 -3,3-difluoropentofuranosyl acetate 7 by the ring-closure reaction under acidic conditions.

217 ortho Br or H atom from PBDEs, followed by a ring-closure reaction, is the most accessible pathway fo

218 reaction step as well as in the free-radical ring-closure reaction.

219 a 4pi-conrotatory Mobius-type electrocyclic ring-closure reaction.

220 also developed utilizing an oxyselenylation ring-closure reaction.

221 N-aryl-2-cyanoazetidines based on an anionic ring-closure reaction.

222 nones, which underwent an effcient 6-exo-tet ring-closure reaction.

223 en cyclase (CLC) chemistry by catalyzing C-C ring closure reactions as opposed to thioester hydrolysi

224 zuki cross coupling and subsequent oxidative ring closure reactions of the perylene units and exhibit

225 ises from simple steric control, whereas the ring-closure reactions are subject to thermodynamic cont

226 Intramolecular ring-closure reactions of the morpholine moiety with the

227 ile ring and for Hof1p-triggered contractile ring closure, rescues the cytokinesis defect observed in

228 ained in terms of photoinduced electrocyclic ring closure resulting in the formation of an intermedia

229 er within the betaine intermediate, prior to ring closure, results in an erosion of ee.

230 om a variety of indolylalkanones underwent a ring closure sequence during FVP to afford 9H-pyrido[2,3

231 catalyzed benzofuran ring opening and furan ring closure sequence for the formation of tri- and tetr

232 ng on reaction conditions, a Michael-Michael ring-closure sequence (MIMIRC) or a net [2 + 4] cycloadd

233 rd substituent at nitrogen failed to undergo ring-closure, several N-protecting groups were evaluated

234 ngs greatly enhances regioselectivity of the ring closure step in comparison to the analogous radical

235 ol phosphate synthase catalyzes the terminal ring closure step in tryptophan biosynthesis.

236 /imination was followed by an acid-catalyzed ring closure step to give the benzimidazole ring.

237 ermediate followed by a slower isomerization-ring closure step to the cyclic aminoxyl radical.

238 while the predicted isotope effects for the ring-closure step are not consistent with the experiment

239 he origin of diastereoselection in the first ring-closure step of these reactions is examined.

240 ggest that the barriers for the addition and ring-closure steps are crudely similar in energy.

241 This includes six C-C ring-closure steps that, through intramolecular Friedel-

242 This includes key high-yielding ring-closure steps which, through intramolecular C-O bon

243 stereochemistry, followed by a methanolysis/ring-closure tandem reaction sequence.

244 further understanding of proton transfer and ring closure tautomerization processes.

245 Our data reveal how RNA-induced ring closure templates a sequential ATP-hydrolysis mecha

246 in the transition state of 4pi electrocyclic ring closure, the oxazolidinone ring and the cyclizing p

247 el role for Aim44p in regulating contractile ring closure through effects on Hof1p.

248 sis by PBP2b and positively regulates septal ring closure through its interactions with StkP-PBP2x.

249 arting point for competition steps involving ring-closure (through a MECP between the open-shell sing

250 lpha position of the amino acid, followed by ring closure to a hydantoin with concomitant explulsion

251 ophile, the cascade process continues beyond ring closure to afford products which have undergone a t

252 ronic acid dienyl bromide 4 led to premature ring closure to afford, after global desilylation, monom

253 B) is predicted to have a lower barrier than ring closure to AH.

254 ity sufficiently activated to allow a second ring closure to be kinetically feasible.

255 form enone 10, and a reductive hydroxyketone ring closure to forge ring V.

256 tetraenes readily undergo 8pi electrocyclic ring closure to form 1,3,5-cyclooctatrienes; however, th

257 the enamines undergo a facile electrocyclic ring closure to form a cyclohexadiene, which goes on to

258 d departs during a subsequent acid-catalyzed ring closure to form a tetracyclic aminal.

259 euteriostyrene sulfide was used to show that ring closure to form cyclic polysulfide incorporated inv

260 tment for methenylation, and Paal-Knorr type ring closure to form the 1,2,2-trimethyl-substituted dih

261 m or sulfenium ion formation, and subsequent ring closure to form the 3(2H)-furanone.

262 annulene, which loses hydrogen and undergoes ring closure to form the anion radical of 11,12-dihydro-

263 orm the C-N bond, while one pathway involves ring closure to form the C-N bond prior to C-Cl bond for

264 nium ion intermediate precedes rate-limiting ring closure to form the cis-aziridine is implicated.

265 e-flask palladium-mediated carbonylation and ring closure to form the imide.

266 photoaddition product; and (3) electrocyclic ring closure to give benzoxanthene derivatives.

267 verse proton transfer (RPT) or electrocyclic ring closure to give dihydrobenzoxanthenes.

268 The latter was found to undergo 5-exo-trig ring closure to give the corresponding 2-methylcyclopent

269 QM that underwent quantitative electrocyclic ring closure to give the corresponding benzoxanthene or

270 ion takes place at C3 of indole, followed by ring closure to give the observed products.

271 This intermediate then undergoes ring closure to give the second equiv of pyridine and fo

272 g partial reduction ring opening followed by ring closure to produce a wide range of annelated benzot

273 PhO(-)) undergo photochemical electrocyclic ring closure to produce a zwitterionic intermediate.

274 ial diradical formation, followed by a rapid ring closure to the more stable cis-fused ring system.

275 ltiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes and quinolines

276 rst demonstration of surface oxametallacycle ring-closure to form EO.

277 Co(III)-carbene radical, followed by radical ring-closure to produce an indanyl/benzyl radical interm

278 voring a particular direction of conrotatory ring closure (torquoselectivity).

279 getic, and electronic features of the 5-endo ring closure transition state.

280 Thus, ring closure uses Myosin-2-dependent and -independent me

281 ) building block, followed by double-"click" ring closure using aryl 3,5-diazides in the presence of

282 cyclizations, we modeled these electrocyclic ring closures using the M06-2X density functional.

283 ergent strategy based on the SmI(2)-mediated ring closure utilized vinyl iodide (-)-26 and aldehyde f

284 mined with the N-(phenyl)fulgimide showing a ring closure value of nearly 0.30 in toluene.

285 ted vinylic to aryl palladium migration, and ring closure via intramolecular arylation or a Mizoroki-

286 d the resulting aldehyde 7 is subjected to a ring closure via reductive amination, providing 1b in an

287 The ring closure was highly stereoselective, leading to the

288 However, ring closure was quickly followed by another beta-scissi

289 ng optimization, the Thorpe-Ingold effect on ring closure was studied using 2,2-dialkyl-1,3-propanedi

290 strates and the stereoselectivities of their ring closures were identified.

291 can be used for an additional Friedel-Crafts ring closure which effectively anneals two extra cycles

292 There is a delay between the ring entry and ring closure, which allows the animal to withdraw from t

293 evealed high activation energy for the third ring closure, which would account for the control of the

294 ide (MgI2) was found to promote irreversible ring closure, while cyclizations using BF3.OEt2 as promo

295 Lewis acid catalyzed ring closure with a thiophene dialcohol in 2% ethanol-di

296 ferences at the transition state and undergo ring closure with divergent stereochemical outcomes.

297 the major cyclopropane product 9b represents ring closure with inversion at C3.

298 formed selectively from alkyl hydrazones by ring closure with Vilsmeier reagent.

299 rown-6 and potassium tert-butoxide undergoes ring closure, with concomitant loss of hydrogen, to yiel

300 e yields a bis-anion, which upon a 5-exo-tet ring-closure yields the desired pyrrolidine, thus comple