ライフサイエンスコーパス: carbene

1 se it generates extremely reactive methylene carbene.

2 the electronic and steric properties of the carbene.

3 ction of benzene and favors formation of the carbene.

4 triplet gap rather than on the nature of the carbene.

5 ss is triggered by lateral metalation of the carbene.

6 te-assisted formation of aryl-Co(III) masked-carbenes.

7 nciple to control the spin state of reactive carbenes.

8 cial metalloenzymes employing iron porphyrin carbenes.

9 s within a range dominated by N-heterocyclic carbenes.

10 to that observed in classical N-heterocyclic carbenes.

11 bilized via strong sigma-donation of singlet carbenes.

12 ith the nucleophilicity of the corresponding carbenes.

13 eAl double bond stabilized by N-heterocyclic carbenes.

14 forms covalent complexes with N-heterocyclic carbenes.

15 The initially formed carbene 22 is estimated to carry chemical activation of

16 hyl)isoquinoline 19 and 1-isoquinolyl-((13)C-carbene) 22, which undergoes carbene-nitrene rearrangeme

17 Once formed, the iron porphyrin carbene accomplishes N-H insertion via nucleophilic atta

18 diaminocarbenes with aroylimines, where the carbene acted as an oxygen-abstracting agent.

19 nalogy with the Skell hypothesis for singlet carbene addition to olefins.

20 y-entropy compensation is operative in these carbene additions.

21 )phosphinidene-isonitrile (>P-P<--:CNR) and -carbene adducts (>P-P<--:C<).

22 peak, conducted to electrogenerated phenacyl carbenes after halide evolution on the first obtained br

23 or 15 enol-ketone pairs derived from various carbenes/aldehydes.

24 rrhenius behavior is proposed to result from carbene-alkene additions taking place intrinsically or e

25 olysis is carried out in cyclohexene but the carbene-alkene cycloadduct could be detected, albeit in

26 noids, carbenic philicity, absolute rates of carbene/alkene additions, the diazirine exchange reactio

27 With the exception of two carbene/alkene combinations, Arrhenius correlations of l

28 s that proceed through dinitrogen extrusion, carbene/alkyne metathesis, and aromatic substitution to

29 the nature and electronic structure of gold carbene/alpha-metallocarbenium complexes and the cationi

30 until recently no examples of cationic gold carbenes/alpha-metallocarbenium ions had been synthesize

31 In contrast, the deuterated (OD) carbene analogue showed much reduced 1,2-D-shift reactiv

32 can be used also for the synthesis of other carbene analogues such as germylenes and phosphinidenes.

33 omologues uniformly electronic structures of carbene analogues that are stabilized by homoconjugation

34 er, shorter, and more polar bond between the carbene and CO2.

35 e the hot reactivity of a metastable Co(III)-carbene and elicit C-C coupling products in a productive

36 e corresponding phosphaketene, phosphinidene-carbene and phosphinidene-phosphine adducts, respectivel

37 p-Tolyl(trifluoromethyl)carbene and the related fluorenyl(trifluoromethyl)carben

38 hydrogen-bonded complex between the singlet carbene and water.

39 ples of tricarbontriphosphide coordinated by carbenes and are likely formed via trimerization of the

40 ecifically the physical organic chemistry of carbenes and carbocations.

41 boraanthracene) stabilized by N-heterocyclic carbenes and its one- and two-electron oxidized congener

42 ns to the surging interest in iron porphyrin carbenes and their synthetic potential.

43 seen original class of stable N-heterocyclic carbenes and, more generally, the potential of electron-

44 ted by an NHC-Cu complex (NHC=N-heterocyclic carbene) and products obtained in 63-95 % yield, 88:12 t

45 zed borylenes are isoelectronic with singlet carbenes, and their reactivity mimics to some extent tha

46 ons, the singlet and triplet states of these carbenes are energetically nearly degenerate in the gas

47 a chiral sulfonate-containing N-heterocyclic carbene, are broadly applicable.

48 l substrates, simply by using N-heterocyclic carbene as ligand, leading to branched products with up

49 ay for the further development of persistent carbenes as universal ligands for silicon and potentiall

50 articular, the development of N-heterocyclic carbene-based emitters and tetradentate cyclometalated P

51 a photochemical reaction that is typical of carbenes bearing a methyl substituent.

52 synthesis of storable bicyclic (alkyl)(amino)carbenes (BICAACs), which feature enhanced sigma-donatin

53 Synthetic application of carbenes, biradicals/radical pairs and carbocations have

54 The existence of the metal-carbene bond could be proven by (13)C-SS-NMR experiments

55 ling the magnetic and chemical properties of carbenes by using light of different wavelengths might b

56 ron carbenes, distinct from other late metal carbenes, C-H cleavage is partially rate-determining and

57 (1; Dipp=2,6-(i) Pr2 C6 H4 ; N-heterocyclic carbene=C[((i) Pr)NC(Me)]2 ) with N2 O furnishes the fir

58 C6 H4 ) and two NHC ligands (N-heterocyclic carbene=:C[(Pr(i) )NC(Me)]2 ) was synthesized in high yi

59 ones, in particular, a cyclic (alkyl)(amino)carbene (CAAC) and an acyclic diaminocarbene (ADAC), are

60 rocyclic carbene (NHC)-cyclic (alkyl)(amino) carbene (CAAC) heterodimers is presented.

61 Cyclic aklyl(amino) carbene (cAAC) is regarded as a stronger sigma-donor and

62 athesis catalysts bearing cyclic alkyl amino carbene (CAAC) ligands was prepared.

63 A cyclic alkyl(amino) carbene (cAAC) stabilized dimer [(cAAC)Si(P-Tip)]2 (2) (

64 The cyclic alkyl(amino) carbene (cAAC) stabilized monoanionic phosphorus atom in

65 e 2 was converted to a cyclic (alkyl) (amino)carbene (cAAC) via 1,2-hydrogen migration triggered by b

66 The reaction of the cyclic (alkyl)(amino) carbene [cAACMe ] (cAACMe =:C(CMe2 )2 (CH2 )NAr, Ar=2,6-

67 nium salts derived from cyclic (alkyl)(amino)carbenes (CAACs) affords propargyl/allenyl radicals.

68 Discovered in 2005, cyclic (alkyl)(amino)carbenes (CAACs) are among the most nucleophilic (sigma

69 le hemilabile bidentate cyclic (alkyl)(amino)carbenes (CAACs) featuring alkene, ether, amine, imine,

70 nd states stabilized by cyclic (alkyl)(amino)carbenes (CAACs).

71 perties compared to monocyclic (alkyl)(amino)carbenes (CAACs).

72 taining predominantly the triplet or singlet carbene can be generated.

73 The carbenes can be generated in both their triplet and sing

74 the diazirine exchange reaction and derived carbenes, carbene equilibria, carbocations from diazotat

75 up to generate stable radical centers on the carbene carbon atoms by employing the so far hidden and

76 d carbonyl ylides formed from intramolecular carbene-carbonyl cyclization in one pot with one catalys

77 ramatically expands the synthetic utility of carbene catalysis by leveraging additional activation mo

78 the presence of alcohols and N-heterocyclic carbene catalysts, e.g., benzimidazolylidenes or triazol

79 MeO/H) (R = MeO, Cl; x = 2, 3), and two free carbenes (catalysts), (OMe2)TPT and (OMe3)TPT, have been

80 Mechanistic aspects of the N-heterocyclic carbenes catalyzed aerobic oxidation of aldehydes shares

81 ulated in 1958, are pivotal intermediates in carbene-catalyzed umpolung.

82 Br, respectively, are transferred to the DPC carbene center and radical pairs are formed.

83 ole of the acceptor substituent flanking the carbene center being the major selectivity determining f

84 on center in PhBCO is isoelectronic with the carbene center in PhCH.

85 skeleton, the steric environment around the carbene center is different from that of CAACs and simil

86 substituents on the heteroatoms flanking the carbene center, as well as inductive electronic effects

87 atom stabilized by binding with the partial carbene-character C atom.

88 s tremendous preparative importance, rhodium carbene chemistry has been studied extensively during pa

89 ngs, which demonstrates the power of rhodium carbene chemistry in organic chemical synthesis.

90 The formally Co(IV) carbene Co(OR)2( horizontal lineCPh2) is formed upon the

91 s at -30 degrees C reveal that 6 forms via a carbene complex (1d) that isomerizes to aminomethyl comp

92 the corresponding Fe(CO)4-modified disilicon carbene complex L:Si horizontal lineSi[Fe(CO)4]:L (6) wi

93 ting and results in an intermediate carbonyl carbene complex.

94 d-shifted component characteristic of a P450-carbene complex.

95 philic attacks to different positions of the carbene complex.

96 ting the substituents present in the initial carbene complex.

97 y determined by the Grubbs second-generation carbene complex: Ru1 was found to promote ene-yne metath

98 1b; RR' = Et2, 1c) react with XylNC to form carbene complexes [PhBP3]Ru(H) horizontal line[C(H)(N(Xy

99 Although the existence of gold carbene complexes as intermediates in gold-catalyzed tra

100 Halo-substituted ruthenium carbene complexes decompose rapidly or deliver low activ

101 ately seven years, a number of cationic gold carbene complexes have been synthesized in solution and

102 n non-heteroatom-stabilized alkynyl chromium carbene complexes prepared in situ and furfural imines t

103 tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experime

104 [2,4,6-trimethylphenyl] substitution on the carbene component.

105 Iron porphyrin carbenes constitute a new frontier of species with consi

106 .g. as accomplished for cyclopentadienyl and carbene derivatives) and a rewarding collaboration betwe

107 participate in rapid migratory insertion of carbenes derived from silyl- or carbonyl-stabilized diaz

108 bearing 2,2'-bipyridyl, 1,10-phenanthroline, carbene, dipyridylamine, pyridyl-benzimidazole, pyridyl-

109 s via a NHC-stabilized (NHC = N-heterocyclic carbene) disilahydronium ion ("pi-bonded" isomer) and is

110 These studies suggest that for iron carbenes, distinct from other late metal carbenes, C-H c

111 As the free carbenes do not react together in solution, the syntheti

112 which the functionality associated with the carbene donor is of the oxygen-donor type.

113 for exploiting gaseous and/or hard-to-handle carbene donor reagents in biocatalytic carbene transfer

114 diazo-1,1,1-trifluoroethane (CF3CHN2) as the carbene donor.

115 rine exchange reaction and derived carbenes, carbene equilibria, carbocations from diazotates, and ca

116 -H insertion reactivity of an iron porphyrin carbene, [Fe(Por)(SCH3)(CHCO2Et)](-), a model of a compl

117 e, first by formation of cyclopropyl gold(I) carbenes, followed by a ring expansion.

118 much improved properties of this probe make carbene footprinting a viable method for rapid and accur

119 In this study a carbene-footprinting approach was developed and applied

120 The carbene forms by dinitrogen loss from ethyl diazoacetate

121 The carbene forms can be easily trapped by the reaction of s

122 Pd-N and capital ES, Cyrillic-N bonds in the carbene fragment XylNCN(R)Xyl.

123 taining pure triplet p-tolyl(trifluoromethyl)carbene from 3 to 25 K leads to an interconversion of up

124 A method based on in situ alkylidene carbene generation-C-H insertion reaction of 5-(3-oxobut

125 Studies on alkylidene carbene generation-C-H insertion reaction of the lactam

126 reaction conditions for effecting alkylidene carbene generation-C-H insertion.

127 he latter react with isonitriles and singlet carbenes giving (phosphino)phosphinidene-isonitrile (>P-

128 We discuss the chemistry of the carbene-gold bond and report on advantages of this new l

129 ormed of rings of 10 carbon atoms bridged by carbene groups yielding seven-membered rings.

130 The stability of the free carbenes has been exploited for the synthesis of copper(

131 on of versatile pyridinium ylides from metal carbenes has been poorly developed; the broad utility de

132 (CAAC)B(CO)Ar] (CAAC = cyclic (alkyl) (amino)carbene), has been prepared using a transfer reaction fr

133 Iron carbenes have been inert, or shown to favor olefin cyclo

134 In recent years, triazolylidene carbenes have come to the forefront as important organoc

135 (MICs) have emerged as an important class of carbene, however they are found in the free form or liga

136 The reaction of 1 with N-heterocyclic carbene IMes afforded 3-(IMes)C14H7O2B(C6F5)2 (11) and [

137 reacts with carbon monoxide, stable singlet carbenes, including the poor pi-accepting imidazol-2-yli

138 oup) secondary C-H bonds by means of rhodium-carbene-induced C-H insertion.

139 nalization of C-H bonds to form C-C bonds by carbene insertion and add carbenes to both beta-substitu

140 tions, namely a diastereoselective dirhodium carbene insertion followed by an ester-directed oxidativ

141 This chemoselective carbene insertion into -NH bond over -COOH and -OH bonds

142 ence of borane-Lewis base complexes, through carbene insertion into boron-hydrogen bonds.

143 compounds under physiological conditions via carbene insertion into silicon-hydrogen bonds.

144 ve been achieved via phosphonate substituted carbene insertion into the N-H bond of aniline catalyzed

145 In order to find an efficient catalyst for carbene insertion reaction in neat water, a large number

146 que example of a net (formal) intramolecular carbene insertion reaction into a vinylic C(sp(2))-H bon

147 nto unactivated C-H bonds and intermolecular carbene insertions into C-H bonds.

148 This activity leads to intramolecular carbene insertions into unactivated C-H bonds and interm

149 yclopropanation by a reactive alpha-oxo gold carbene intermediate generated in situ.

150 (3))-H bond to a C(sp(3))-C bond via an iron carbene intermediate represents a long-standing challeng

151 tation into a highly reactive alpha-oxo gold carbene intermediate.

152 (sp(3))-H alkylations via isoelectronic iron carbene intermediates have thus far been unsuccessful.

153 pplication of steady-state conditions to the carbene intermediates provided a rate treatment that fit

154 tion, consistent with rapid decomposition of carbene intermediates under ene-yne conditions.

155 or amino acids is caused by stabilization of carbene intermediates via the carbonyl group.

156 carbene, due to competitive insertion of the carbene into the N-N bond.

157 dium in place of iron catalyze insertions of carbenes into C-H bonds with up to 98% enantiomeric exce

158 The selectivity of the title carbene is compared with that of spiro[2.3]hex-4-ylidene

159 The carbene is investigated in argon matrices by IR, UV-vis,

160 The dual-ringed carbene is predicted to assume four distinct geometric c

161 Bis(p-methoxyphenyl)carbene is the first carbene that at cryogenic temperatu

162 An alternative way to generate the singlet carbene is the reaction of the triplet with water molecu

163 of a silicon(I) radical with N-heterocyclic carbenes is described.

164 uding diazoalkane derivatives and alkylidene carbenes, it is possible to induce novel Grob-type C-C f

165 and also electrophilic (pi-accepting) stable carbenes known to date.

166 particular the relative contributions of the carbene (LAu(+)[double bond, length as m-dash]CR2) and a

167 of a rhodium pre-catalyst, an N-heterocyclic carbene ligand and an amino-pyridine co-catalyst.

168 Addition of the N-heterocyclic carbene ligand IMes to fac,anti-(ONO(Cat))Re(O)(mu-O)2Re

169 roducts result from insertion of a palladium-carbene ligand into the N-H bond of the aromatic N-heter

170 Subsequent rearrangement of the carbene ligand is rate limiting for electron poor and st

171 ed electrons residing on the iron center and carbene ligand.

172 (I) atom of 2 into the Cphenyl-N bond of the carbene ligand.

173 cursor supported by a monoanionic pincer bis(carbene) ligand, (Mes)CCC ((Mes)CCC = bis(mesityl-benzim

174 sed cobalt pre-catalysts with N-heterocyclic carbene ligands catalyze the Suzuki cross-coupling of ar

175 ection for 'Privileged chiral N-heterocyclic carbene ligands for asymmetric transition-metal catalysi

176 ridine or benzoquinoline) and N-heterocyclic carbene ligands possess intriguing structures, topologie

177 tiple bond to give, after rearrangement, the carbene-ligated Al(III) amide, NacNac'Al(NHTol)(SIMe) (6

178 sized from the combination of N-heterocyclic carbene-ligated gold(I) trimethylsilylchalcogenolates [(

179 on, the first examples of the gold mesoionic carbene mediated [2+2+2] cycloaddition of these enynes w

180 vel Grob-type C-C fragmentations, alkylidene carbene mediated Li-N insertions, and dipolar cycloaddit

181 This work expands the range of carbene-mediated transformations accessible via metallop

182 tigations support that an electrophilic iron carbene mediates homolytic C-H cleavage and rebounds fro

183 polymerization (ROMP) with cyclometalated Ru-carbene metathesis catalysts were investigated.

184 Neutral mesoionic carbenes (MICs) have emerged as an important class of ca

185 carbazole framework flanked by two mesoionic carbenes (MICs).

186 neous gold-catalyzed processes incorporating carbene migratory insertion steps.

187 lineP bond, while the LUMO is located at the carbene moiety (cAAC or NHC).

188 cter with non-negligible spin density on the carbene moiety.

189 in the chemical conversion of N-heterocyclic carbene molecules attached to catalytic particles is map

190 ve groups in surface-anchored N-heterocyclic carbene molecules.

191 to amine products form via an intramolecular carbene N-H insertion, and the imidazopyrrolopyrazines f

192 opyrrolopyrazines form via an intermolecular carbene N-H insertion.

193 eveal that a 1,2-phenyl shift in the singlet carbene needs to overcome a barrier of only 3.8 kcal/mol

194 mediated radical reactions of N-heterocyclic carbene (NHC) boranes.

195 N-Heterocyclic carbene (NHC) catalysis has emerged as a powerful strata

196 als was realized using chiral N-heterocyclic carbene (NHC) catalysts.

197 Three N-heterocyclic carbene (NHC) catalyzed kinetic resolutions (KR) and one

198 ediated metalation (AMMM) and N-heterocyclic carbene (NHC) chemistry, a novel C-N bond activation and

199 15 years the success story of N-heterocyclic carbene (NHC) compounds in organic, inorganic, and organ

200 gy-based index of the ease of N-heterocyclic carbene (NHC) formation either by deprotonation of precu

201 nyl)phenyl) stabilized by the N-heterocyclic carbene (NHC) ImMe4 is reported.

202 Here, we show that N-heterocyclic carbene (NHC) Ir(III) complexes can serve as both deep b

203 The use of an electron-rich N-heterocycilc carbene (NHC) ligand is effective to inhibit undesired b

204 Dissymmetry at the N-heterocyclic carbene (NHC) ligand was identified as a key parameter f

205 It is well-recognized that N-heterocyclic carbene (NHC) ligands have provided a new dimension to t

206 ontal Be-Be axis supported by N-heterocyclic carbene (NHC) ligands.

207 ion between N-aryl triazolium N-heterocyclic carbene (NHC) precatalysts and substituted benzaldehyde

208 turated 2,6-diisopropylphenyl N-heterocyclic carbene (NHC) precursors with excellent selectivity (up

209 A fused pi-helical N-heterocyclic carbene (NHC) system was prepared and examined through i

210 nk the dicarbollide ion to an N-heterocyclic carbene (NHC) to form an isolable N-dicarbollide-substit

211 N-Heterocyclic carbene (NHC)-catalyzed intramolecular aldol lactonizati

212 ional investigations into the N-heterocyclic carbene (NHC)-catalyzed proton-transfer polymerization (

213 mide and ester equivalents in N-heterocyclic carbene (NHC)-catalyzed redox hetero-Diels-Alder reactio

214 The synthesis of N-heterocyclic carbene (NHC)-cyclic (alkyl)(amino) carbene (CAAC) heter

215 and characterization of novel N-heterocyclic carbene (NHC)-gold(I) complexes and their bioconjugation

216 We report the N-heterocyclic carbene (NHC)-induced activation of an otherwise unreact

217 ensive characterization of an N-heterocyclic carbene (NHC)-modified supported heterogeneous catalyst.

218 when compared with that of an N-heterocyclic carbene (NHC).

219 = 1,5-cyclooctadiene) and an N-heterocyclic carbene (NHC).

220 N-Heterocyclic carbenes (NHC's) are known to serve as efficient substra

221 e of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as wel

222 The success of achiral N-heterocyclic carbenes (NHCs) as stable electron-rich neutral ligands

223 e of formation of (i) neutral N-heterocyclic carbenes (NHCs) by deprotonation of heterocyclic salts a

224 and stabilized by two capping N-heterocyclic carbenes (NHCs) has been prepared.

225 ganic films on gold employing N-heterocyclic carbenes (NHCs) has been previously shown to be a useful

226 unctional theory computations.N-heterocyclic carbenes (NHCs) have been applied as ancillary ligands i

227 eterocyclic phosphenium) with N-heterocyclic carbenes (NHCs) leads to phosphaheteroallenes (NHP)-O-P=

228 M{N(SiMe3 )2 }2 ] (M=Fe, Co), N-heterocyclic carbenes (NHCs) react with primary phosphines to give a

229 nt in functionalizing gold by N-heterocyclic carbenes (NHCs), a promising alternative ligand class re

230 ifferent donor groups, and of N-heterocyclic carbenes (NHCs).

231 clic amido-chlorosilylene bis(N-heterocyclic carbene) Ni(0) complex [{N(Dipp)(SiMe3 )ClSi:-->Ni(NHC)2

232 quinolyl-((13)C-carbene) 22, which undergoes carbene-nitrene rearrangement to 2-naphthylnitrene 23.

233 tom transfer, and transition-metal-catalyzed carbene/nitrene transfer, for the directed functionaliza

234 Carbenes of platinum and palladium, PtC3 and PdC3 , were

235 or to the class of mononuclear half-sandwich carbenes of Rh(III), which show considerable potential.

236 and a2); and path b via ring closure of the carbene onto the ring nitrogen, yielding 1-aza-benzo[d]b

237 nt carbon atom, typically formulated as gold carbenes or alpha-metallocarbenium ions, have been widel

238 with primary phosphines to give a series of carbene phosphinidenes of the type (NHC)PAr.

239 The fact that diazo compounds and other carbene precursors are known mechanism-based inhibitors

240 Here, the imidazolium-carbenes preferentially react with the disulfide bond, b

241 ds indicate that ring-contraction within the carbene prevails over ring-expansion by a factor of 6.7:

242 Placing the carbene producing 21-diazo/triazolo moiety of the photop

243 g to the calculation, and the N-heterocyclic carbene quinoline-2-ylidene is not formed as a tautomer.

244 ntrolled radical ring-closure process of the carbene radical intermediate involved.

245 age of the intrinsic reactivity of a Co(III) carbene radical intermediate.

246 DBPO) confirm the involvement of cobalt(III) carbene radical intermediates.

247 e investigated, which demonstrates catalytic carbene radical reactivity for a nonporphyrin cobalt(II)

248 o compound leading to formation of a Co(III)-carbene radical, followed by radical ring-closure to pro

249 ro[3.3]hept-1-ylidene is a markedly strained carbene reaction intermediate that was generated by high

250 The index described previously (carbene relative energy of formation) has been extended

251 This index (CREF; Carbene Relative Energy of Formation), which is easily c

252 Magnetic bistability of carbenes seems to be a general phenomenon that only depe

253 to either the dirhodium(II) tetracarboxylate carbene series that enjoys widespread preparative use, o

254 onium salts in 40-94 % yields from mesoionic carbene silver complex and Aryl-I-Py2 (OTf)2 .

255 haves like a silver-bound aryl cation or 1,2-carbene-silver carbenoid.

256 ism mediated by an electrophilic, heme-bound carbene species and a model is provided to rationalize t

257 followed by isomerization to yield transient carbene species, one of which was confirmed by trapping

258 ment, one which involves the intermediacy of carbene species.

259 r on the chemical character of the resulting carbenes species is documented by the structures of a ho

260 The cyclic alkyl(amino) carbene stabilized Si2H2 has been isolated in the molecu

261 double bond, was achieved by reduction of a carbene-stabilized 1,1'-bis(dihaloboryl)ferrocene.

262 ptical and electrochemical properties of the carbene-stabilized diborene unit.

263 Reaction of thiolate 1 with carbene-stabilized diiodo-bis-silylene (2) (in a 2:1 rat

264 While reaction of carbene-stabilized disilicon L:Si horizontal lineSi:L (L

265 )Pr2C6H3)CH}2) (8) with HCl.NC5H5 results in carbene-stabilized Si2Cl2 (2) and substituted 1H-imidazo

266 yclopropanes (boriranes) with N-heterocyclic carbene substituents were prepared by a recently discove

267 Bis(p-methoxyphenyl)carbene is the first carbene that at cryogenic temperatures can be isolated i

268 arly, we now describe the first example of a carbene that exhibits differing thermal and photochemica

269 hiazol-2-ylidene, which is an N-heterocyclic carbene that has high-affinity for and is presumed to be

270 s (the conjugate acids of the triazolylidene carbenes) that have not been heretofore examined in vacu

271 e that among different classes of persistent carbenes, the more electrophilic and nucleophilic ones,

272 lectivity of the [2 + 2]cycloaddition of the carbene to the quinoid substrate is highly dependent on

273 form C-C bonds by carbene insertion and add carbenes to both beta-substituted vinylarenes and unacti

274 inactivation pathways of heme protein-based carbene transfer catalysts should aid in the optimizatio

275 ing new enzymes for a variety of non-natural carbene transfer reactions has burgeoned.

276 y patterns like 1,3-carbonyl transpositions, carbene transfer reactions, cascade annulations, macrocy

277 andle carbene donor reagents in biocatalytic carbene transfer reactions.

278 e results constitute an entry into catalytic carbene transformations from oxidized methylene precurso

279 s than about 90 kcal/mol and to proceed by a carbene-type mechanism.

280 tivated metal dihydride featuring a neutral (carbene-type) N-heterocyclic Ga(I) ligand.

281 It does not originate from the carbene under HVFP conditions.

282 The carbene undergoes two [1,2]-sigmatropic rearrangements v

283 idatively generated beta-diketone-alpha-gold carbenes using ynones as substrates.

284 For fluorenyl(trifluoromethyl)carbene, very similar results are obtained, but the yiel

285 The charge-tagged carbene was generated in situ in a tandem mass spectrome

286 c studies indicated that formation of the Ir-carbene was reversible and the slow step of the reaction

287 rst isolable, photoswitchable N-heterocyclic carbene was synthesized and found to undergo reversible

288 ation 20 times greater than when a ruthenium carbene was used.

289 of novel beta-carboline-based N-heterocyclic carbenes was prepared via Mannich reaction between methy

290 carbohydrates by the 1,5 insertion of metal-carbenes, we report herein the robust and scalable conve

291 ne and the related fluorenyl(trifluoromethyl)carbene were synthesized in solid argon and characterize

292 The carbenes were generated by falling solid flash vacuum py

293 ts in formation of predominantly the triplet carbene, whereas visible (450 nm) light shifts the photo

294 mperature, produces (alpha-methylbenzylidene)carbene which undergoes a facile Fritsch-Buttenberg-Wiec

295 he key intermediates are cyclopropyl gold(I) carbenes, which have been independently generated by ret

296 at the diazo functional group to form a gold carbene whose subsequent cascade process (intramolecular

297 erated in situ from the coupling of a copper-carbene with a spirocyclic thietane.

298 ting parameters that are typical for triplet carbenes with axial symmetry (|D/hc| = 0.63 cm(-1), |E/h

299 The reaction of rhodium-bound carbenes with strained bicyclic methylene aziridines res

300 Ph3 ]X, rare terminal phosphorano-stabilized carbenes with thorium.