ライフサイエンスコーパス: ring closure

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

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

3 is described using diphosgene to induce the ring closure.

4 and type II myosins and promotes contractile ring closure.

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

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

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

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

9 synthesized using two different methods for ring closure.

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

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

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

13 red throughout cytokinesis until contractile ring closure.

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

15 which after oximation undergo acid-catalyzed ring closure.

16 2-formylbenzeneboronates followed by McMurry ring closure.

17 ponsible for the diastereoselectivity of the ring closure.

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

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

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

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

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

23 mellitic triimides via dehydration and imide ring closure.

24 modynamic preference for the hexenyl radical ring closure.

25 through a sequence of Pd-allyl transfer and ring closure.

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

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

28 an alternative palladium-catalyzed oxidative ring closure.

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

30 dition of the nucleophile, ring opening, and ring closure.

31 rovide high enantiofacial selectivity in the ring closure.

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

33 The reverse occurs in ring closure.

34 c macrocyclization substrate for 49-membered ring closure.

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

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

37 emoselective nitrogen functionalization, and ring closure.

38 eroxide intermediates followed by hemiacetal ring closure.

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

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

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

42 P are both required to cooperatively promote ring closure.

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

44 nsible for lowering the energetic barrier to ring closure.

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

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

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

48 ration of an oligonucleotide duplex enhances ring-closure.

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

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

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

52 essed to enable otherwise challenging medium ring closures.

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

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

55 es explains the reduced selectivity of these ring closures.

56 clizations for sequential CD (8:1 dr) and DE ring closures (14:1 dr) that benefit from both preorgani

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

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

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

60 stry because the high entropic cost of large-ring closure allows undesired intermolecular reactions t

61 Ring closure also changes the interface between the stal

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

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

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

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

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

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

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

69 it remains unclear how those proteins guide ring closure and how they promote subsequent formation o

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

71 ifying the self-assembly protocol to promote ring closure and secondary nucleation, a maximum catenat

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

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

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

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

76 enzymes catalyzing initial C10-C1 or C11-C1 ring closures and clade II enzymes catalyzing C6-C1 clos

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

78 ano-4-(methylthio)-2-arylpyrimidin-6-ones 4, ring closure, and further optimization led to the identi

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

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

81 Using the late stage ring closure approach, an S-linked analogue of methyl ne

82 edge reveals that the barriers for the peri-ring closure are slightly higher, even though the peri-a

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

84 4pai-electrocyclization and not a 5-endo-dig ring closure as had been proposed in the literature.

85 Via a photoinitiated ring closure, benoxacor initially yields a monochlorinat

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

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

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

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

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

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

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

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

94 oup affects the possibility of a 10-membered ring closure by the Nicholas reaction.

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

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

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

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

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

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

101 Ring closure correlated with the viability and migration

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

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

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

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

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

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

108 Ring closure experiments demonstrated that looping requi

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

110 esting a triplet pathway for the conrotatory ring closure followed by a suprafacial [1,4] hydrogen mi

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

134 d an aldehyde or a ketone and the subsequent ring closure, is an important reaction in organic chemis

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

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

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

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

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

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

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

142 The plausible ring closure mechanism was examined with quantum chemica

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

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

145 In no example was ring closure observed to operate.

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

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

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

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

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

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

152 Oxidative ring closure of alkyl-substituted 2-hydroxyacetophenone

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

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

155 The ring closure of domino protocol was highly stereoselecti

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

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

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

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

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

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

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

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

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

165 ulopyranosylamine)onamides by intramolecular ring closure of the aldimine moieties with the carboxami

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

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

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

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

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

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

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

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

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

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

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

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

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

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

180 Ring closure of vinylogous derivative 12 in the presence

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

215 -3,3-difluoropentofuranosyl acetate 7 by the ring-closure reaction under acidic conditions.

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

217 mine, followed by a Grignard-mediated double ring-closure reaction.

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

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

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

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

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

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

242 thesized using a novel acid-promoted cascade ring closure strategy, and then copolymerized with a ben

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 ion assist in the additional dehydrogenative ring closures that yield a new planarized decacyclic dia

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

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

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

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

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

252 d TBD/ethyl trifluoroacetate mediated lactam ring closure to afford a representative GSM in high yiel

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

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

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

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

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

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

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

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 mediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture.

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

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

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

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

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

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 he first time, employing either a late stage ring closure to install the required 3,6-anhydro-bridge

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

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

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

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

277 al results suggest the aldehydic H-shift and ring-closure to produce an epoxide functionality could b

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

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

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

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

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

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

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

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

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

287 The ring closure was highly stereoselective, leading to the

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

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

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

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

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

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

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

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

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

297 ring opening along the N-N bond, followed by ring closure with the formation of new C-N bonds.

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