ライフサイエンスコーパス: nitrene

1 evidence of a tunneling reaction involving a nitrene.

2 to the formation of the closed-shell singlet nitrene.

3 The S(1) state decays to produce the singlet nitrene.

4 dride transfer to the rhodium-complexed acyl nitrene.

5 ene N-oxide intermediates as well as triplet nitrene.

6 sed as the tether between the alkene and the nitrene.

7 stepwise Curtius rearrangement via the free nitrene.

8 riplet energy transfer to form triplet alkyl nitrene.

9 of the singlet from the lower-energy triplet nitrene.

10 ucts from the conversion of azido ligands to nitrenes.

11 ploits the high electrophilicity of sulfinyl nitrenes.

12 hed light on the electronic structure of the nitrenes.

13 lower energy singlet state for each of these nitrenes.

14 orption spectra of the corresponding singlet nitrenes.

15 nitrenes relax to the corresponding triplet nitrenes.

16 formation of the corresponding triplet alkyl nitrenes (1-n), via intramolecular energy transfer from

17 trene radical cation, (pi*)(4)(delta*)(2)(pi(nitrene,1))(1)(pi(nitrene,2))(0).

18 ated triplet nitrene, (pi*)(4)(delta*)(1)(pi(nitrene,1))(1)(pi(nitrene,2))(1).

19 1f), which serves as a reservoir for singlet nitrene 1b.

20 More specifically, nitrene 2 does undergo alpha-photocleavage to form benzo

21 The secondary photolysis of nitrenes 2 is further supported with molecular modeling

22 eads to selective formation of triplet alkyl nitrenes 2 that were detected directly with laser flash

23 Nitrenes 2 were further characterized with argon matrix

24 t benzoyl radicals 3 can also be formed from nitrenes 2.

25 on, (pi*)(4)(delta*)(2)(pi(nitrene,1))(1)(pi(nitrene,2))(0).

26 ne, (pi*)(4)(delta*)(1)(pi(nitrene,1))(1)(pi(nitrene,2))(1).

27 The thermally generated nitrene 23 is observed directly by matrix-isolation ESR

28 sient absorption spectra due to formation of nitrene 2a (lambdamax=320 nm) and benzoyl radical 3a (la

29 ay of 3a is 2 x 105 s-1 in methanol, whereas nitrene 2a decays with a rate of approximately 91 s-1.

30 In a hydrophobic environment singlet nitrene 2a partitions between forming triplet nitrene 3a

31 Nitrene 2a, with an n,pi* configuration as the lowest tr

32 none (1b) releases the corresponding singlet nitrenes 2a and 2b.

33 om recombination of benzoyl radicals 3a with nitrenes 2a.

34 Singlet nitrene 2b reacts with the unactivated CH bonds of cyclo

35 The lifetime of nitrene 2b was measured to be 16 ms.

36 sis of tetrafluoro azide 1b releases singlet nitrene 2b, which has a lifetime of 172 ns in benzene an

37 in azide 1b leads to energy transfer to form nitrene 2b; however, alpha-cleavage is not observed sinc

38 to the lower-energy and longer-lived triplet nitrene (3)(2-NpSO(2)N).

39 itrene 2a partitions between forming triplet nitrene 3a and an acyl-substituted didehydroazepine 4a,

40 s, respectively) to the lower energy triplet nitrenes 3a and 3b, intermediates which do not react to

41 and 525-527, positioning the photogenerated nitrene a maximum of 19-26 A from the complemented rRNA

42 Regeneration of the nitrene active species by reaction of ArN3 with the meta

43 y exothermic reactions with ArN3 to form the nitrene active species.

44 re formed by copper-catalyzed intramolecular nitrene addition to alkenes.

45 ines from alkylallenes derive from catalytic nitrene addition to the allene double bonds.

46 traction from substrate C-H bonds or initial nitrene-addition to one of the olefinic carbons.

47 calculations reveal a predominantly triplet nitrene adduct bound to copper(I), as opposed to copper(

48 n, (3) alkene and alkyne polymerization, (4) nitrene and carbene group transfer, (5) fundamental tran

49 extremely slow thermal reaction between the nitrene and O2 was observed, whereas at higher temperatu

50 s an extremely valuable method of generating nitrenes and studying their thermal rearrangements.

51 ittings of more than 20 substituted aromatic nitrenes and the radical stabilizing ability of the arom

52 between the singlet and triplet state of the nitrene, and oxygen quenching experiments suggest that t

53 long that N-N coordinate to form the singlet nitrene, and with a barrier of only approximately 5 kcal

54 ition metal-catalyzed transfers of carbenes, nitrenes, and oxenes are powerful methods for functional

55 Nitrene- and carbene-generating photolinkers were invest

56 The closed-shell singlet and triplet nitrene are separated by a small energy gap in protic so

57 The products from these two nitrenes are derived from the corresponding singlet nitr

58 doyl, boryl, silyl, phosphonyl, and sulfonyl nitrenes are included.

59 n-reactivity of a nitrene-trap suggests that nitrenes are not generated and thus a reductive eliminat

60 The triplet nitrenes are persistent at 77 K and their spectra were r

61 The triplet alkyl nitrenes are persistent intermediates that do not abstra

62 , indicating that singlet states of aromatic nitrenes are preferentially stabilized by radical stabil

63 ational spectra of the corresponding triplet nitrenes, azirines, and didehydroazepines were observed,

64 bond-forming/-reduction sequences as well as nitrene-based C-H amination methods.

65 which ensures formation of the triplet alkyl nitrene by bypassing the singlet nitrene intermediate.

66 ell as the corresponding singlet and triplet nitrenes by CBS-QB3 and B3LYP computational methods.

67 tion outcome can be understood by assuming a nitrene C-H insertion within a hydrogen-bonded silver co

68 nzyme, can catalyze olefin aziridination and nitrene C-H insertion, and that these activities can be

69 and aminations via high-valent iron oxos and nitrenes, C(sp(3))-H alkylations via isoelectronic iron

70 The nitrenes can in many cases be isolated in low-temperatur

71 A variety of Huisgen cyclization or nitrene/carbene alkyne cascade reactions with different

72 ixth ligand bound to cobalt(III) in the mono-nitrene case remains elusive, but some plausible candida

73 nor (4b)) without evidence of imidyl or free nitrene character.

74 corresponding oxadiazole, is the predominant nitrene chemistry, occurring on the time scale of a few

75 zidopyridine 1-oxide is dominated by triplet nitrene chemistry.

76 mu-N(t)Bu) (3) demonstrate that the terminal nitrene [Cl2NN]Cu horizontal lineN(t)Bu is the active in

77 etrical parameters consistent with a triplet nitrene complex of Rh(2).

78 hesis show a greater tendency toward triplet nitrene complexes and hence the potential for metal-free

79 Terminal copper- and silver-nitrene complexes have long been proposed to be the key

80 Metal-mediated decomposition to form nitrene complexes is investigated by using DFT for proto

81 trongly suggest the intermediacy of reactive nitrene complexes of the type [SiP(iPr)(3)]Fe(NAr) that

82 d dipyrrin ligand to produce terminal copper nitrene complexes with near-linear, short copper-nitreno

83 ing bridging and terminal copper- and silver-nitrene complexes, which are characterized by NMR spectr

84 nsertion transition states with different Ag nitrene complexes.

85 nitrene nor the subsequently formed triplet nitrene contribute to cross-link formation.

86 Dicopper nitrenes [Cu]2(mu-NCHRR') derived from 1 degrees and 2 d

87 fluorinated azide 1b can form useful singlet nitrene derived adducts upon photolysis.

88 enching experiments suggest that the triplet nitrene derives from the triplet excited state of the su

89 e a highly electrophilic intermediate as the nitrene donor and a symmetrical aziridine-like transitio

90 s are derived from the corresponding singlet nitrene, either directly or via thermal repopulation of

91 Direct observation of the triplet nitrene, energetic differences between the singlet and t

92 the intermediacy of sulfinyl nitrenes, with nitrene formation proceeding via a transient triplet int

93 henyl, the contribution of the nitrosamine/O-nitrene-forming pathway was diminished.

94 We report a metathesis reaction in which a nitrene fragment from an isocyanide ligand is exchanged

95 rom an isocyanide ligand is exchanged with a nitrene fragment of an imido ligand in a series of niobi

96 sts because they serve as a useful source of nitrene fragments and interesting nitrene rearrangement

97 ce signal by using CL-activated formation of nitrenes from azides to locally fix a fluorescent probe

98 he spin-selective photogeneration of triplet nitrenes from azidoformates.

99 Thermally persistent triplet sulfonyl nitrene, FSO(2)N, was produced in the gas phase in high

100 eivably lacks sufficient reactivity with the nitrene generated from the probe.

101 d formation via reactive iron-bound carbonyl nitrenes generated from nature-inspired acyl-protected h

102 Although nitrene generation by exhaustive deoxygenation is widely

103 The nitrene generation from azide 5 occurs on the S(2) surfa

104 lylborate ligand catalyzes the transfer of a nitrene group from PhI=NTs to the Si-H bond of silanes,

105 proposed intermediate and its viability as a nitrene group transfer reagent are supported by intermol

106 nal nitrenes [(i) Pr2 NN]Cu=NAr that undergo nitrene group transfer to PMe3 , (t) BuNC, and even into

107 mediates, which further incorporate a second nitrene group, both processes being silver-mediated.

108 mido complex that can engage in simultaneous nitrene-group transfer and oxygen-atom transfer to gener

109 d phenyl isocyanate, causing sulfur-atom and nitrene-group transfer, respectively.

110 he slippery potential energy surface of aryl nitrenes has revealed unexpected and fascinating reactio

111 lnitrene RS(O)N, a highly reactive alpha-oxo nitrene, has been rarely investigated.

112 otolysis of 1 reveals that the triplet alkyl nitrenes have absorption around 300 nm.

113 In contrast, nonmetallic nitrenes have so far only been spectroscopically observe

114 4 and 8 to be "masked" forms of the terminal nitrenes [(i) Pr2 NN]Cu=NAr that undergo nitrene group t

115 with bulkier azides N3 Ar leads to terminal nitrenes [(i) Pr2 NN]Cu]=NAr that dimerize via formation

116 es intersystem crossing (ISC) to the triplet nitrene in aprotic and protic solvents as well as proton

117 FVT of the azide produces the nitrene in high yield and with only minor contaminations

118 ions equal the rates of decay of the singlet nitrenes in 88% formic acid and are as follows: p-biphen

119 report the first detection of triplet alkyl nitrenes in fluid solution by laser flash photolysis of

120 Nitrenes included within octa acid attack one of the fou

121 Transition-metal-catalyzed C-H amination via nitrene insertion allows the direct transformation of a

122 roducts are formed via a rare intramolecular nitrene insertion into an adjacent methoxy C-H bond foll

123 dines via dirhodium catalyzed intramolecular nitrene insertion into sp(3) C-H bonds.

124 yed successfully to afford the corresponding nitrene insertion product in good yield, albeit low in f

125 ct to improve the efficiency of a late-stage nitrene insertion reaction.

126 Enantioselective nitrene insertion to allylic/propargylic C-H bonds was a

127 ategy involves graphene-oxide/I(2)-catalyzed nitrene insertion using PhINTs as a nitrene (NT) source

128 transition metals (Pd, Pt, Rh, etc.) such as nitrene insertions or C-C and C-heteroatom coupling reac

129 ed us to characterize the C-N stretch of the nitrene intermediate at 1201 cm(-)(1).

130 earrangement versus the loss of N2 to form a nitrene intermediate provides strong evidence that the c

131 tion, which can be mediated by a high-valent nitrene intermediate such as a Co(III) iminyl ((Ar)L)CoB

132 recently, the Lewis acid adduct of a copper-nitrene intermediate was trapped at -90 degrees C and sh

133 iplet alkyl nitrene by bypassing the singlet nitrene intermediate.

134 Nitrene intermediates 2N_L and 3N_L are also examined by

135 es H-atom abstraction from R-H substrates by nitrene intermediates [Cu](kappa(2) -N,O-NC(O)Ar) to pro

136 Iron imide/nitrene intermediates [Fe(qpy)(NR)(X)](n+) (CX, X = NR,

137 The triplet alkyl nitrene intermediates are also trapped with molecular ox

138 electronic structure of the proposed copper-nitrene intermediates has also been controversially disc

139 The electronic structures of these putative nitrene intermediates have been examined by DFT methods.

140 High-valent copper-nitrene intermediates have long been proposed to play a

141 amination is hypothesized to proceed via Rh2-nitrene intermediates in either the Rh2(II,II) or Rh2(II

142 ns but selectively yields only triplet alkyl nitrene intermediates that dimerize to form 3b.

143 ngement of allylic hydrazides, via singlet N-nitrene intermediates, is reported.

144 involves the insertion of metal carbenes and nitrenes into C-H bonds.

145 The resulting nitrene is a powerful base and abstracts protons extreme

146 2N_L and 3N_L are also examined by DFT (the nitrene is an NSO3R species).

147 are in the interior of the cavity where the nitrene is generated, and in CB7 they are at the exterio

148 A nitrene is likely the aminating species responsible for

149 cis-4-octene suggest that reactivity of the nitrene is mainly through the singlet channel, despite a

150 ions 2252-2253, such that the photogenerated nitrene is maximally 17-19 A from 23S RNA nucleotides G2

151 rted process is only 27 kcal/mol, and a free nitrene is not produced upon pyrolysis of acetyl azide.

152 products that are frequently observed if the nitrene is produced by photolysis.

153 The putative Ag-nitrene is proposed to undergo enantiodetermining hydrog

154 ead, we favor a mechanism in which free aryl nitrene is released during the catalytic cycle and combi

155 The singlet nitrene is too short-lived to be observed and, thus, to

156 reaction, in which an electrophilic rhodium nitrene is trapped by an alkyne, resulting in the format

157 bility of the closed-shell singlet states in nitrenes is shown by Natural Resonance Theory to be very

158 inodimethane, and not the singlet or triplet nitrene, is the pivotal reactive intermediate involved i

159 of nearby singlet and triplet states of the nitrene itself.

160 1.0] bicycle intermediate derived from Ir(V) nitrene-mediated aziridination to be a key intermediate

161 Each specific EPI-nitrene-modified site involved either Tyr195 of loop C o

162 ido complex was effective for delivering the nitrene moiety to both C-H bond substrates (42% yield) a

163 itrene radical species is able to transfer a nitrene moiety to phosphines and abstract a hydrogen ato

164 intramolecular one-electron transfer to the "nitrene" moiety, but now from the porphyrin ring instead

165 ansfer from the cobalt(II) porphyrin to the 'nitrene' moiety (Ns: R'' = -SO2-p-C6H5NO2; Ts: R'' = -SO

166 stabilizes the triplet state of the carbonyl nitrene more than the corresponding singlet state.

167 ally unstable and decomposed to form triplet nitrenes NCN and NNC as well as triplet carbenes NCCCN,

168 o the imine is a concerted process without a nitrene/nitrenoid intermediate.

169 Neither the initially produced singlet nitrene nor the subsequently formed triplet nitrene cont

170 atalyzed nitrene insertion using PhINTs as a nitrene (NT) source in water at room temperature.

171 ate has the shortest lifetime of any singlet nitrene observed to date and is a true reactive intermed

172 t the viability of organic cycloadditions of nitrenes onto the diamond (100) surface.

173 bonds is to insert a monovalent N fragment (nitrene or nitrenoid) into a C-H bond or add it directly

174 Our findings suggest that an Rh-nitrene oxidant can react with hydrocarbon substrates th

175 chanical calculations suggest a plausible Rh-nitrene pathway.

176 reductive cyclization of nitroaromatics, non-nitrene pathways have only been theorized previously.

177 Concomitantly, the nitrene PhNBN is formed via phenyl rearrangement.

178 One EPI-nitrene photoactivated molecule was incorporated in each

179 3N is Rh2(II,III) with a coordinated triplet nitrene, (pi*)(4)(delta*)(1)(pi(nitrene,1))(1)(pi(nitren

180 cobalt(III)-TAML complexes with PhINNs as a nitrene precursor leads to TAML-centered oxidation and p

181 s developed utilizing 1,2,3,4-tetrazole as a nitrene precursor via iron catalysis.

182 served as the silver source, PhI=NNs as the nitrene precursor, and 1,10-phenanthroline as the coliga

183 thoxysulfonyl (Tces)-protected carbamimidate nitrene precursor, coupled with the appropriate ligand f

184 s novel route involves the use of azide as a nitrene precursor, electronically-controlled regioselect

185 catalyst activates N-benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular

186 Azidoformates are interesting potential nitrene precursors, but their direct photochemical activ

187 to involve the formation of an intermediate nitrene prior to alkyl or aryl migration show no evidenc

188 ding evidence of the reactivity of the azido/nitrene probe substituent and close proximity to both re

189 The four photoactivated nitrene probes modified AChBP with up to one agonist for

190 osamine (R(2)NN=O) and an oxygen-substituted nitrene (R'ON).

191 e GES of 2N as Rh2(II,II) with a coordinated nitrene radical cation, (pi*)(4)(delta*)(2)(pi(nitrene,1

192 or TAML(sq)) determines whether mono- or bis-nitrene radical complexes are formed.

193 eads to TAML-centered oxidation and produces nitrene radical complexes without oxidation of the metal

194 Thus, the formation of the second nitrene radical involves another intramolecular one-elec

195 The terminal copper(II)-nitrene radical species is able to transfer a nitrene mo

196 ic characterization of a terminal copper(II)-nitrene radical species that is stable at room temperatu

197 These nitrene radical species were characterized by EPR, XANES

198 To fully characterize the Co(III)-'nitrene radical' species that are proposed as intermedia

199 e best described as [Co(III)(por)(NR''(*-))] nitrene radicals (imidyl radicals) resulting from single

200 results in one-electron-reduced Fischer-type nitrene radicals (N(*)Ns(-)) that are intermediates in c

201 hree ligand-centered unpaired electrons: two nitrene radicals (NR''(*-)) and one oxidized porphyrin r

202 ontrol to carbonyl O-oxides, whereas triplet nitrenes react much slower.

203 l azides are efficient sources for the metal nitrene reactive intermediate.

204 s above 40 K, and at these temperatures, the nitrene reacts with O2 to produce nitroso O-oxide mainly

205 elective oxyamination reaction with the same nitrene reagent generated in stoichiometric amounts.

206 lsion chemistry, and the isolation of formal nitrene rearrangement products of "1-AdN", "2-AdN" and "

207 source of nitrene fragments and interesting nitrene rearrangement products.

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

209 In aqueous solutions singlet nitrenes relax (1.1 ps and 43 ns, respectively) to the l

210 At 77 K, the singlet nitrenes relax to the corresponding triplet nitrenes.

211 3)C label distribution requires that the non-nitrene route b contributes significantly.

212 te that an active, but still elusive, copper-nitrene (S = 1) intermediate initially abstracts a hydro

213 ent; in the presence of a 200-fold excess of nitrene scavenger, photoprobe 1 inactivates 92% of the K

214 t and diphenylphosphoryl azide (DPPA) as the nitrene source has been developed.

215 on with diphenylphosphoryl azide (DPPA) as a nitrene source.

216 Conversion of mono-nitrene species 3(P1)(Ns) into bis-nitrene species 5(P1)

217 (Troc) (TrocN3) led to the formation of mono-nitrene species 3(P1)(Ns), 3(P2)(Ts), and 3(P2)(Troc), r

218 s) results again in formation of mainly mono-nitrene species 3(P2)(Ns) according to EPR and ESI-MS sp

219 n of mono-nitrene species 3(P1)(Ns) into bis-nitrene species 5(P1)(Ns) upon reaction with 4(Ns) was d

220 lineNNs) 4(Ns) led to the formation of a bis-nitrene species 5(P1)(Ns).

221 ruling out the possibility of a common metal nitrene species and instead suggesting a rhodium-nitreno

222 XANES data revealed that both mono- and bis-nitrene species are six-coordinate O(h) species.

223 ron-deficient aryl azides renders the copper nitrene species competent for alkane amination and alken

224 High-valent terminal copper-nitrene species have been postulated as key intermediate

225 Interestingly, this bis-nitrene species is observed only on reacting 4(Ns) with

226 n is mediated by a catalytic dirhodium-bound nitrene species that first behaves as a Lewis acid.

227 eaction starts with the formation of a metal-nitrene species that holds some radical character, and t

228 The mono- and bis-nitrene species were initially expected to be five- and

229 Upon generation at 10 K, the triplet nitrene spontaneously rearranges in the dark to singlet

230 on proceeds at rt without external oxidants, nitrene stabilizing groups, or directing functionality.

231 transfer to generate an open-shell singlet "nitrene-substrate radical, ligand radical", enabling sub

232 denosine diazaquinodimethane, the product of nitrene tautomerization, has a lifetime of ca. 1 min or

233 do not undergo ring expansion but form basic nitrenes that protonate to form nitrenium ions.

234 oxazolones on the Cu catalyst generates acyl nitrenes that rapidly insert into the copper acetylide C

235 ther securing intramolecular addition of the nitrene, the intermolecular C-H amination remains much l

236 f abundant oxime, via rearrangement of the O-nitrene to a C-nitroso compound (R'ON --> O=NR'), and su

237 he photoinduced Curtius rearrangement of the nitrene to FNSO(2) was observed in solid noble gas matri

238 do decay by dimerizing with another triplet nitrene to form azo products, rather than reacting with

239 e intramolecular [1,4] H atom shift from the nitrene to the imino ketene occurs by tunneling, on the

240 ally abstracts a hydrogen atom from, or adds nitrene to, C-H and C horizontal lineC bonds, respective

241 indicate that [Mn((t)BuPc)] transfers bound nitrenes to C(sp(3))-H bonds via a pathway that lies bet

242 Nitrene transfer (NT) reactions represent powerful and d

243 totypical radical-promoted reactivity (e.g., nitrene transfer and H-atom abstraction), where the dive

244 turnovers, ranking among the most efficient nitrene transfer biocatalysts reported to date.

245 ual role for the Rh(2)L(n) complex as both a nitrene transfer catalyst and a Lewis acid promoter, ins

246 Nitrene transfer from core imides is negligible.

247 capitalizing on an efficient stereoselective nitrene transfer involving the combination of a chiral a

248 e development of new catalysts for selective nitrene transfer is a continuing area of interest.

249 Asymmetric C-H amination via nitrene transfer is a powerful tool to prepare enantioen

250 ts derived from a cytochrome P450 that use a nitrene transfer mechanism for the enantioselective amin

251 Olefin aziridination via organocatalytic nitrene transfer offers potential complementarity to met

252 This species undergoes clean nitrene transfer on treatment with tert-butyl- or di-iso

253 n nitrogenated ligands can be used to tune a nitrene transfer reaction between two different types of

254 ext] We report here the first gold-catalyzed nitrene transfer reaction.

255 pecies that are proposed as intermediates in nitrene transfer reactions mediated by cobalt(II) porphy

256 stent with their proposed key involvement in nitrene transfer reactions mediated by cobalt(II) porphy

257 ilver-catalyzed, nondirected, intermolecular nitrene transfer reactions that are both chemoselective

258 lvability of the catalyst toward challenging nitrene transfer reactions.

259 reactions, as evidenced by the reaction with nitrene transfer reagents to form tantalum imido species

260 ns of cobalt(II) complexes of porphyrins and nitrene transfer reagents were combined, and the generat

261 of these bis(imido) complexes also promotes nitrene transfer to catalytically generate asymmetric di

262 Fe(kappa(2)-N4Ad2), undergoes intermolecular nitrene transfer to phosphine, abstracts H atoms from we

263 *)Ns(-)) that are intermediates in catalytic nitrene transfer to styrene.

264 e of efficient metal-mediated intermolecular nitrene transfer to such substrates.

265 iocatalysts for mediating C-H aminations via nitrene transfer, a valuable transformation for forging

266 sfer, and transition-metal-catalyzed carbene/nitrene transfer, for the directed functionalization of

267 ight into the nature of iminium catalysis of nitrene transfer.

268 r histidine unlocks non-natural carbene- and nitrene-transfer activities.

269 trongly basic guanidinato moieties, mediates nitrene-transfer from PhI horizontal lineNR sources to a

270 the intermediacy of this species in proposed nitrene-transfer mechanisms.

271 Asymmetric nitrene-transfer reactions are a powerful tool for the p

272 as their putative intermediacy in catalytic nitrene-transfer reactions.

273 w promising scaffolds for the development of nitrene transferases and demonstrates the value of mecha

274 ses of aminooxazoles based on gold-catalyzed nitrene transfers to ynamides to furnish 4-amino-1,3-oxa

275 pomer cross-over and the non-reactivity of a nitrene-trap suggests that nitrenes are not generated an

276 As a result, the unreactive triplet state nitrene undergoes delayed, thermally activated reverse I

277 The singlet nitrene undergoes intersystem crossing (ISC) to the trip

278 r with chemoselectivity for insertion of the nitrene units into C-H bonds over reduction of the azide

279 product 11 indicates that 1 forms a singlet nitrene upon photolysis.

280 these complexes (lambda > 280 nm) results in nitrenes via the loss of nitrogen from the guest azidoad

281 Involvement of the O-nitrene was confirmed by trapping with 2,3-dimethyl-2-bu

282 g the reaction of phenylnitrene with O2, the nitrene was generated by flash vacuum thermolysis (FVT)

283 The intermediacy of the O-nitrene was inferred from the production of abundant oxi

284 vidence of products arising from the singlet nitrene was observed, indicating a slow rate of cyclizat

285 The triplet alkyl nitrenes were further characterized by obtaining their U

286 solution releases the corresponding singlet nitrene which rapidly tautomerizes to form a closed aden

287 ambient temperature again produces a singlet nitrene, which is too short-lived to detect by nanosecon

288 to reform the reactive closed-shell singlet nitrene, which subsequently protonates, forming the rema

289 talysts results in the formation of reactive nitrenes, which can undergo a variety of C-N bond-formin

290 It is unlikely that the nitrenes will undergo a Curtius-like rearrangement becau

291 rises from interception of the triplet alkyl nitrene with benzoyl radicals.

292 lid noble gas matrices, and reactions of the nitrene with O(2), NO, and CO were studied.

293 d by photoactivation of the azide group to a nitrene with single-pulse UV laser excitation.

294 Combining sulfinyl nitrenes with carbon and nitrogen nucleophiles enables t

295 modynamics and kinetics suggests that nickel-nitrenes with fluorinated phosphine supporting ligation

296 ion about exchange interactions in high-spin nitrenes with the pyrimidine ring and the mechanism of t

297 gations support the intermediacy of sulfinyl nitrenes, with nitrene formation proceeding via a transi

298 The behavior of nitrenes within OA differs from that in solution.

299 Reactivity of nitrenes within OA is different from that of carbenes th

300 yield LNi = NX + Y (L = bis-phosphine, NX = nitrene, Y = N2 or IPh).