ライフサイエンスコーパス: sigma bond

1 of halogen bond acceptors (lone pair, pi and sigma bonds).

2 ple of the protonation of an element-element sigma bond.

3 eta-alkyl migration steps that break the C-C sigma bond.

4 alpha-substituent centers (A-B) is only the sigma bond.

5 the nucleophile to the backside of the C--Cl sigma bond.

6 over-limiting C=C/CC insertion into the An-N sigma-bond.

7 ith either the aromatic pi-system or the C H sigma-bond.

8 lting in selective hydrogenolysis of the C-C sigma-bond.

9 e Sn-Sn-C angles which may shorten the Sn-Sn sigma-bond.

10 the acceptor is reduced by one carbon-carbon sigma-bond.

11 organoboronic ester substituent across a C-C sigma-bond.

12 ly simple electronic structure of just Si-Si sigma bonds.

13 which contain two-center, two-electron Ln-B sigma bonds.

14 alizations, result in the cleavage of strong sigma bonds.

15 are the first iron-sulfur clusters with Fe-C sigma bonds.

16 ctroscopy, they readily couple to form final sigma bonds.

17 all-ring formation and insertion into strong sigma bonds.

18 graphene layers and connecting them via C-C sigma bonds.

19 good lone pair electron donor toward geminal sigma bonds.

20 hypervalent 4-center 6-electron S...S-S...S sigma-bonds.

21 traps represent one-electron intermolecular sigma-bonds.

22 dization tendencies that yield the strongest sigma-bonds.

23 space in a bonding way, but do not form full sigma-bonds.

24 lities into lanthanide-alkyl and -heteroatom sigma-bonds.

25 Pd-Ge sigma-bonds and two delocalized 4c-2e sigma-bonds.

26 -H, N-H, O-H, C-C, C-N, and C-F, among other sigma-bonds.

27 makes Kalpha RIXS a more sensitive probe of sigma-bonding.

28 d state via a series of zinc-pi (1) and zinc-sigma-bonded (2) bridging interactions.

29 ations, can be described by two horizontally sigma-bonded 2p(x) and 2p(y) orbitals along with one per

30 NMR chemical shift calculations support the sigma-bonded 9 as the global minimum.

31 tructure and bonding interactions in the U-C sigma-bond across this series of complexes.

32 by quinoline-directed, rhodium-catalyzed C-C sigma bond activation.

33 xes and metal NPs in their reactivity toward sigma-bond activation and functionalization.

34 rivatives of this class involve at least one sigma-bond activation elemental step, whereas two sequen

35 Carbon-carbon sigma-bond activation is a contemporary challenge for or

36 nesium(I) compounds are reported for the C-C sigma-bond activation of strained alkylidene cyclopropan

37 ery example of transition metal mediated C-C sigma-bond activation reported to date, the reaction occ

38 ss-coupled with an aryl triflate through C-C sigma-bond alkoxy- or aminopalladation with concomitant

39 vealing the strong deshielding effect of the sigma-bonded alkyl ligands on the scandium nuclei.

40 acceptor E-E bond (E = S, Se, and Te) whose sigma bond already has its bond pair electrons.

41 d changed polarity of the phenyl-substituent sigma bond alter the interaction (the Wheeler-Houk pictu

42 he metal center at one end by a metal-carbon sigma bond and at the other by one three-center M-H-B in

43 ylate by a monodentate terphenyl forms a M-C sigma bond and creates a coordination unsaturation at th

44 nating peripheral bonds, with a weak central sigma bond and significant diradical character.

45 oiety converts the nitrogen lone pair into a sigma bond and the HOMO into a lower-lying orbital that

46 stable electrical contact between the Si-Si sigma bond and the other electrode.

47 ecules the orbital corresponding to the Re-H sigma bond and the Re-H vibrational mode is very localiz

48 de tethers between the carbons forming a new sigma bond and the release of ring strain from opening o

49 e molecule shows that a rearrangement to one sigma bond and two lone pairs on sulfur is usually more

50 on as a triple bond consisting of a covalent sigma bond and two strong pi back-donations.

51 s the linear interdependence of covalent M-P sigma bonding and bond distance.

52 incorporation in 3 and 4 involves tin-carbon sigma bonding and is shown to be fully reversible under

53 cell in this regard: no fewer than three new sigma bonds and a new ring system are formed from simple

54 Gd13Fe10C13 build a picture of covalent Fe-C sigma bonds and conjugated pi systems for which Lewis st

55 talytic aminoboration of C-C pi bonds by B-N sigma bonds and its application to the synthesis of 3-bo

56 ge-bearing units that are doubly linked by 4-sigma-bond and by 6-sigma-bond saturated bridges are com

57 -carbene bond, lead to a higher-lying NHC-Au sigma-bond and lower-lying pai*-orbital, ultimately yiel

58 n), which serve as prototypical examples of sigma-bonded and pai-bonded backbones, respectively.

59 e nonclassical, implicating the dominance of sigma-bonding and absence of pi-back-bonding.

60 The combination of axial trans sigma-bonding and pi-bonding effects that include expans

61 tal step, whereas two sequential ruptures of sigma-bonds and the cross-coupling of the resulting frag

62 ght be key for the efficient scission of C-S sigma-bonds and the origin of diastereoselectivity.

63 In this process, three new sigma-bonds and three new stereogenic centers were gener

64 Ge(9) ligands is provided by six 2c-2e Pd-Ge sigma-bonds and two delocalized 4c-2e sigma-bonds.

65 ionalized 2-piperidinones containing two new sigma-bonds and two vicinal quaternary stereogenic cente

66 containing both alkene pi-bonds and allylic sigma-bonds, and the ene yields are higher with 1 than w

67 pecies with 2-center, 3-electron (2c/3e(-) ) sigma bonds are of interest owing to their fascinating e

68 pai-bonds are well established, additions to sigma-bonds are far less explored.

69 of such reactions is challenging because C-C sigma-bonds are typically unreactive.

70 s energetically preferred over the eta(1) - (sigma-bonded) arrangement, but the Mg must be in a low c

71 Sigma-bonded arrays are compared to conventional pi-bond

72 The six-coordinate nitrosyl sigma-bonded aryl(iron) and -(ruthenium) porphyrin compl

73 Enhancement of acceptor ability of C-X sigma bonds as one moves from left to right in periods p

74 ion and activation of apolar or weakly polar sigma-bonds at copper using chelating assistance.

75 lanar fragment consists of three 2c-2e Pd-Ge sigma-bonds attaching Pd atoms to the core Ge atom, whil

76 This simple picture of acceptor ability of sigma bonds being controlled by electronegativity in per

77 are limited examples of highly strained C-C sigma-bonds being used in difunctionalization reactions.

78 s S = 1 and 2) by two strong pi and a strong sigma bond between Fe(IV) and the oxo ligand.

79 resulting in formation of a direct covalent sigma bond between the carbon backbone and the gold meta

80 drazones that allows for the generation of a sigma bond between two unfunctionalized sp(3) carbons in

81 n the two Fe atoms, a bridging sulfur, and d(sigma)-bonding between Fe centers.

82 y differ by the presence or absence of a C-C sigma-bond between the unpaired electrons of the parent

83 alkane sigma-complexes, where an alkane C-H sigma-bond binds to the metal.

84 perreduced Pt(pop-BF2)(6-) a very rare 6p(2) sigma-bonded binuclear complex.

85 aphite transition owing to the similarity of sigma-bond breakage into a delocalized pi-system.

86 ane(6) (4) with LiNaph/THF establishes a B-B sigma bond but can be accompanied by substituent redistr

87 e in that it lacks the typical Rh(II)-Rh(II) sigma bond, but significant orbital overlap between the

88 to weaken and facilitate the reaction of C-C sigma-bonds, but there are limited examples of highly st

89 volves in the intramolecular cleavage of two sigma-bonds (C-O and C-C) and inter/intramolecular const

90 In general, relative donor abilities of sigma bonds can be changed by their through-bond communi

91 As a result, the acceptor ability of sigma bonds can be significantly modified by substitutio

92 anium contribution to the U horizontal lineC sigma-bond can increase from ca. 18 to 32% and within th

93 e to gain better knowledge regarding the way sigma-bonds can be activated by copper to help further d

94 strate that the strong donor ability of C-Ge sigma-bonds can be used to raise the energy of the ancho

95 precedented fundamental reaction step: a C-C sigma-bond carbopalladation.

96 al of the electrostatically-bound K-ion; the sigma-bond changes little but the pai-bond is significan

97 and subsequently undergo phosphate-sugar O-C sigma bond cleavage, it is highly unlikely (in contrast

98 C-S sigma-bond cleavage of partially unsaturated sulfur-cont

99 =O pi orbital and induce phosphate-sugar O-C sigma bond cleavages if the phosphate groups are rendere

100 aracterization and dynamic rearrangements of sigma-bond complexes, most notably alkane and zincane co

101 iers leading to fluxional structures between sigma-bonded configurations or sigma- and pi-bonded conf

102 are the methodologies centered on C(1)-C(2) sigma-bond construction and C(2)-R/Ar bond-forming proce

103 lated by a combination of sigma hole and n-->sigma* bonding contributions with retention of the octet

104 tivation of H-H, Si-H, and C-H bonds through sigma-bond coordination has grown in the past 30 years f

105 By contrast, only weaker sp(2)-sp(2) sigma bonds could form in unobserved concerted transitio

106 lding a standard enthalpy of formation of di-sigma bonded cyclohexene on Pt(111) at low coverages of

107 At 100 K, cyclohexene adsorbs as intact di-sigma bonded cyclohexene on Pt(111), and the heat of ads

108 duction during the oxidative addition of E-H sigma-bonds (E = C, N, O, Si, P).

109 bit transition-metal-like insertion into E-H sigma-bonds (E = H, N, Si, B, P, C, O) with formation of

110 lve the activation of apolar or weakly polar sigma-bonds (E-H and E-E' bonds, with E = C, B, Si, Sn,

111 H2 to a metal center via polarization of its sigma bond electron density, known as a Kubas complex, i

112 interact with filled f-orbitals raising the sigma-bond energy.

113 Di-sigma-bonded ethene and pi-bonded ethene on the clusters

114 Di-sigma-bonded ethylene reacts with carbene species, forme

115 theory calculations, indicate that a single sigma-bond exists between the M(III) centers and the oxo

116 array of p orbitals arranged tangentially in sigma-bonding fashion.

117 pounds with up to four rotationally hindered sigma bonds, for which a single stereoisomer out of seve

118 inct pathway for oxyboration that avoids B-O sigma bond formation and enables this catalyst-free rout

119 electrophilic cyclization, as opposed to S-B sigma bond formation, providing a mechanistically distin

120 ition states (TSs) are early with respect to sigma bond formation.

121 pi-MO of 3 that is primarily responsible for sigma-bond formation in 4, not the terminal allenyl pi-b

122 cking pancake multicenter bond formation and sigma-bond formation.

123 alpha-carbon occurs concomitantly with C-Pd sigma-bond formation.

124 All sigma-bond formations were found to proceed through high

125 The sigma-bond formed in this process corresponds to the pro

126 e B-H sigma-bond is broken in favor of a B-C sigma-bond, forming Cp*W(CO)(2)(H)(C(5)H(11)-Bpin), a tu

127 The review ends with speculation that sigma-bond-forming reactions may also be observed someda

128 g to three rings, almost never engage in new sigma-bond-forming reactions.

129 ed by two Kekule structures sharing a common sigma bond framework, the square Al(4)(2-) structure has

130 the triflate moiety is channeled through the sigma-bond framework of 1, providing direct access to th

131 thereby completing synthetic cycles for C-C sigma-bond functionalization.

132 ulene metal complexes featuring metal-carbon sigma bonds has been obstructed not only by the syntheti

133 organouranium aryl complexes containing U-C sigma-bonds has been of interest to the chemical communi

134 Difunctionalization reactions of C-C sigma-bonds have the potential to streamline access to m

135 es (four lone pairs) and features homoatomic sigma-bond heterolysis, thereby combining the key featur

136 A case study of catalytic carbon-carbon sigma-bond homolysis is presented.

137 ride reagent is presented, which may undergo sigma-bond homolysis upon visible-light-induced sensitiz

138 n protocols via thermal or photochemical M-C sigma-bond homolysis, radical formation is triggered sol

139 trogen atoms that are separated by only four sigma bonds if its nitrogens were planar.

140 y involves concerted addition of 5b across a sigma bond in 14b via 35.

141 rongly M-Cl sigma antibonding and weakly M-M sigma bonding in character.

142 metal cations, in which 3-center-2-electron sigma bonding in Ge(2) Zn or Ge(2) Cd triangles plays a

143 The acceptor ability of the C-X sigma bonds in monosubstituted ethanes increases when go

144 lar magnitude influences acceptor ability of sigma bonds in monosubstituted ethenes in a complex way.

145 ations of the controlled rotation around the sigma bonds in retinal moiety and its generalizability t

146 tal evidence agrees with involvement of only sigma bonds in these transformations.

147 the opportunity that exists to form sp-sp(2) sigma bonds in transition structures 21 and 23 that lead

148 re transfer of the first electron from a C-H sigma-bond in methane to one of the metal centers.

149 nover-limiting C-C insertion into an M-N(H)R sigma-bond in the transition state.

150 excellent opportunity to study the degree of sigma-bonding in a metalloboratrane as a function of ele

151 r type of functionality, thereby forming two sigma-bonds in a single reaction sequence.

152 The Cu-O sigma-bonds in the mu3-oxo-bridged structure would provi

153 igma-hole is located on the extension of the sigma-bond, in the hypervalent species our DFT calculati

154 allows asymmetric difunctionalization of C-C sigma-bonds, including dicarbonation and carboboration.

155 rganoiron intermediate, where the subsequent sigma bond insertion of dioxygen into the C-Fe bond comp

156 stem (Ea = 1.1-2.4 kcal/mol) rather than C-C sigma-bond insertion into the cyclopropenyl moiety (Ea =

157 an unprecedented chemoselective C(sp(2))-Ar sigma-bond insertion of the alkene.

158 e cycloadditions, nucleophilic additions and sigma-bond insertions.

159 However, the Pt-Pt sigma bonding interaction is limited by the relatively l

160 es of molecules wherein very close C-F---H-C sigma-bond interactions, which we have termed "jousting"

161 ure description for NiSOD(ox) reveals strong sigma-bonding interactions between Ni and the equatorial

162 enue for catalyst regeneration from the Au-C sigma-bond intermediate, in contrast to other Au-catalyz

163 les of vibrational structure in metal-ligand sigma-bond ionizations are observed in the gas-phase pho

164 nd how the concerted scission of the central sigma bond is prevented in the boat conformation.

165 nalization of the adjacent C(sp(3))-C(sp(2)) sigma bonds is much rarer.

166 The large 2p character of the azide sigma bonds is responsible for the particularly high N(b

167 are achieved because a covalent Au-C sigma (sigma) bond is formed.

168 In this configuration, the B-H sigma-bond is broken in favor of a B-C sigma-bond, formi

169 ia a diradicaloid transition state where one sigma-bond is made before a second.

170 Y and La and 4f(3) Nd congeners only MIC-->M sigma-bonding is found.

171 rgy required for the interconversion of the "sigma-bonded" isomer into a putative NHC-stabilized disi

172 arbons of opposing aryl groups evolve into a sigma bond leading to the formation of the biaryl anion

173 lexes are regularly isolated with classical, sigma-bonded ligands, and this has been thought to be th

174 nantly ionic, with covalent character in the sigma-bonding Ln-B HOMO.

175 Examples of sigma-bonds made of a single electron delocalized over t

176 ystem of triplet O2, the weakness of the O-O sigma bond makes reactions of O2, which eventually lead

177 en site-pair that cleaves the C-H bond via a sigma bond metathesis reaction, during which the Co inse

178 Similarly, Co clusters also catalyze the sigma bond metathesis step, but much less effectively be

179 oxidative addition/reductive elimination or sigma-bond metathesis are disfavored.

180 The reaction is therefore viewed as a formal sigma-bond metathesis between an N-H bond of ammonia and

181 osed to proceed through hydroalumination and sigma-bond metathesis between the resultant alkenyl alum

182 also shown that on the Au(111) surface this sigma-bond metathesis can be combined with Glaser coupli

183 C-H bond activation via sigma-bond metathesis is typically observed with transit

184 DFT calculations support a sigma-bond metathesis mechanism during transmetalation a

185 A sigma-bond metathesis mechanism has been proposed in all

186 We propose a sigma-bond metathesis mechanism in which an Fe-H interme

187 nd theoretical results support a bimolecular sigma-bond metathesis mechanism in which the phenolic pr

188 tion of tert-butyl acetylene by an insertion/sigma-bond metathesis mechanism involving [((i)Pr(2)-ATI

189 ly exoenergetic (-55 kcal/mol), and reveal a sigma-bond metathesis mechanism to be unfavorable compar

190 cleavage process occurs by a metal-assisted sigma-bond metathesis mechanism to generate a borane com

191 ies easily activates H-H and Si-H bonds by a sigma-bond metathesis mechanism, which was further confi

192 pentane), undergoes C-H bond activation by a sigma-bond metathesis mechanism--in 16 micros, a termina

193 ion (prevalent with B-X electrophiles); (ii) sigma-bond metathesis mediated (prevalent with B-H and B

194 anism is characterized by a rate-determining sigma-bond metathesis of an alkoxide complex with the si

195 erein, we disclose the first examples of the sigma-bond metathesis of silylated alkynes with aromatic

196 reversible for the minor isomer pathway, and sigma-bond metathesis of the metallacycle Ni-O bond with

197 DFT studies suggest a complex assisted sigma-bond metathesis pathway for C(sp(2))-H bond activa

198 de 1-OSiPh3 apparently via an unconventional sigma-bond metathesis pathway in which the Ni center is

199 ce of H(2) carrier gas was consistent with a sigma-bond metathesis pathway.

200 ly unsaturated metal centres at the SBUs via sigma-bond metathesis pathways and as a result of the st

201 sed in terms of classical and unconventional sigma-bond metathesis pathways.

202 ophile and the metal as nucleophile, mediate sigma-bond metathesis pathways.

203 d nickel metallacycle followed by sequential sigma-bond metathesis processes involving the two Si-H b

204 The sigma-bond metathesis reaction of 13 with Mes2SiH2 yield

205 aining alkene and subsequent silylation by a sigma-bond metathesis reaction, affording the observed p

206 ribution at silicon, and chemoselectivity in sigma-bond metathesis reactions, are discussed.

207 uggest that borylation occurs via successive sigma-bond metathesis steps, whereby a Pt(II) -H interme

208 ssociation of coordinated alkene followed by sigma-bond metathesis to form H2 and Zr-allyl.

209 hen undergoes B-C bond formation by a second sigma-bond metathesis to generate the final functionaliz

210 er ligand is created by a pair of Ar-H/Ta-Me sigma-bond metathesis transformations, rather than by a

211 support a pathway proceeding via a concerted sigma-bond metathesis transition state, where the base c

212 ism proceeding by hydrocupration followed by sigma-bond metathesis with a hydrosilane.

213 dative addition to H-abstraction and then to sigma-bond metathesis with increasing O-content, as acti

214 e transesterification of vanadate occurs via sigma-bond metathesis, and vanadium enolate is directly

215 d: oxidative addition, heterolytic cleavage, sigma-bond metathesis, electrophilic attack, etc.

216 protonated by tBuOH to induce a ring-opening sigma-bond metathesis, giving an alumina-substituted P-h

217 polymerization catalysts and underlines that sigma-bond metathesis, olefin insertion, and olefin meta

218 -O(ox), cleave C-H bonds heterolytically via sigma-bond metathesis, with Pd(2+) adding to the C-H bon

219 tallographically verified, a snapshot of the sigma-bond metathesis.

220 utene and cyclopropane) with Ph(2)SiH(2) via sigma-bond metathesis.

221 by intermolecular alpha-mono-borylation via sigma-bond metathesis.

222 efin insertion, indicating its similarity to sigma-bond metathesis.

223 lectron transfer, halogen atom transfer, and sigma-bond methatesis.

224 ma* orbital of E-X as emphasized in the 'n-->sigma*' bonding model.

225 calculations confirmed the preference of the sigma-bonding model of alkyne and further revealed the f

226 Flexible sigma-bonded molecular junctions typically occupy straig

227 e between chromophores, since rotation about sigma bonds negligibly affects the orbital overlap withi

228 reactions often involve coordination of the sigma bond of dihydrogen, silanes (Si-H), or alkanes (C-

229 gnesium-catalyzed hydrosilylation of the C-C sigma bonds of alkylidene cyclopropanes.

230 acts with H-X (X = H, Si, B, Al, C, N, P, O) sigma bonds of H2, silanes, borane (HBpin, pin = pinacol

231 aryl palladium(II) complex interacts with a sigma-bond of a strained bicyclo[1.1.0]butyl boronate co

232 1a, and the CO2 insertion into the alpha-C-H sigma-bond of amine 1a.

233 reaction, which reductively aminates the C-C sigma-bond of carbonyls, not the carbonyl C-O pai-bond,

234 irectly exploit the polarized reverse-dative sigma-bond of metal-borane complexes (i.e., M-->BR3 ) re

235 unctionalization of the strained central C-C sigma-bond of the bicyclo[1.1.0]butyl unit.

236 ults from Ti-N pai-bonding mixing with N-C-N sigma-bonding of the bent N-C-N framework.

237 The angles between the three sigma-bonds of the carbon sp(2) orbitals are roughly 120

238 ion of the unsubstituted vertices as well as sigma-bonds of the cluster framework of 4.

239 rough a formal [2+2] cycloaddition involving sigma bonds only (two C-H bonds and two aryl-halogen bon

240 These studies also show that the C-C sigma bonding orbital of the radical cation contains onl

241 an electron is removed from the Re-H or Re-D sigma-bond orbital.

242 at extension of the MCSCF methods to include sigma bonding orbitals or virtual-orbital CI brings MCSC

243 ctions between Lewis orbitals (predominantly sigma bonding orbitals).

244 l of an electron from the predominantly Re-H sigma-bonding orbitals.

245 with a diatropic ring current following the sigma-bond path formed by Si 3p orbitals.

246 ed breakdown of pai-stacking by formation of sigma-bonded polymers.

247 itution" (CEIS) in which the gold(III)-furyl sigma-bond produced by furan auration acts as a nucleoph

248 the chemisorption process involves M[bond]C sigma-bond protonolysis at the strong surface Bronsted a

249 i-intermediate 10 is higher than that of the sigma-bonded reactant 9 by approximately 2 kcal/mol acco

250 ctive difunctionalization of the central C-C sigma-bonds remains challenging.

251 Here we present an analogue theory for sigma bond resonance in flat boron materials, which allo

252 i.e. unbridged) cobalt-cobalt three-electron sigma bond, respectively, each with a formal bond order

253 s of reversible beta-hydride elimination and sigma-bond rotation processes that occur following a rar

254 n conditions enable alkene C(sp(3))-C(sp(2)) sigma bond-rupturing cross-coupling reactions for the co

255 r/intramolecular construction of two/one C-C sigma-bond(s).

256 t are doubly linked by 4-sigma-bond and by 6-sigma-bond saturated bridges are compared with ones havi

257 tracyclic product imply rotations around two sigma bonds (sigma(C-C) and sigma(C-N), bonds beta and a

258 on that activate the C-C pi bond and the B-N sigma bond simultaneously.

259 ffanes are composed of weakly conjugated C-C sigma-bonds, staffanes carry a shallower conductance dec

260 The consecutive thermal migration of two sigma-bonds (stepwise dyotropic rearrangement) is an exa

261 ) at low coverages of -135 kJ/mol and a C-Pt sigma bond strength of 205 kJ/mol.

262 9.0 kcal/mol), although one of the two tetra-sigma-bonded structures (-26.7 kcal/mol) is similar in e

263 action products indicates that the two tetra-sigma-bonded structures (that are energetically comparab

264 conversion of the [4+2] product to the tetra-sigma-bonded structures entails huge barriers (>37.0 kca

265 dates ([2+2] adduct, [4+2] adduct, two tetra-sigma-bonded structures, and one radical-like structure)

266 isms were discovered via which the initially sigma-bonded substrate could be converted: oxidative add

267 etallic variants exhibiting a polar covalent sigma bond supplemented by up to two dative pai bonds ar

268 ned by three independent delocalized (pi and sigma) bonding systems, each of which satisfies the 4n +

269 erate isomerization (topomerization) of the "sigma-bonded" tautomers of 1H[B(Ar(F))4], which proceeds

270 rder analysis and partitioning reveals 4c-2e sigma bonds that stabilize the two-dimensional structure

271 lectronic properties of the sulfur-methylene sigma bonds that terminate the molecule.

272 the bonding in 2 reveals, in addition to the sigma bond, the presence of a single classical pai bond

273 nes, that contain strongly interacting Si-Si sigma bonds, the essential components of the bulk semico

274 ability of polyhydride complexes to activate sigma-bonds, the vast majority of the reactions catalyze

275 a single operation, to two new carbon-carbon sigma-bonds, three new stereogenic centers, and two new

276 ormation enables the introduction of two C-C sigma bonds through C-H bond activation and sequential a

277 ons result in the formal addition of the C-C sigma bond to the main group center either at a single s

278 differences in geometry that reflect pseudo-sigma bonding to the Fe(III) and relate to reactivity.

279 ation reaction, the addition of boron-oxygen sigma bonds to alkynes.

280 For nearly 70 years, the addition of boron-X sigma bonds to carbon-carbon multiple bonds has been emp

281 al Rh and Ir complexes that feature 2c/3e(-) sigma bonds to the Si atom of a tripodal tris(phosphine)

282 from neutron diffraction data contains a B-H sigma-bond to iridium with an elongated B-H bond distanc

283 kly pi-bonded on monolayer Ni/Pt(111) but di-sigma-bonded to Pt(111) and Ni(111).

284 Ph, that is pi-bonded to the osmium atom and sigma-bonded to the platinum atom.

285 acilitate adsorption of terminal alkynes via sigma-bonding to the surface Ag atoms.

286 of copper to promote the addition of apolar sigma-bonds to CC multiple bonds via a 2e redox sequence

287 Although two examples of sigma-bonded trans-bent [RSbSbR](*-) (R = bulky organo-

288 functionalities of groups 2 to 16 and a few sigma-bonded transition metal complexes are experimental

289 method for generating angular forces around sigma-bonded transition metal ions is generalized to tre

290 al intermediate that readily reacts with N-H sigma bonds under catalytically relevant conditions.

291 Homoleptic sigma-bonded uranium-alkyl complexes have been a synthet

292 sults demonstrate activation of this boron-O sigma bond using a gold catalysis strategy that is funda

293 ossibility of heteronuclear B-C one-electron sigma-bonding, we have prepared a naphthalene-based plat

294 p-character of orbitals comprising the Sn-Sn sigma-bond when the Sn-Sn-C angle is decreased by ca. 30

295 atoms between graphite layers pair and form sigma-bonds, whereas the nonbridging carbon atoms remain

296 pi-bonds between graphite layers convert to sigma-bonds, whereas the other half remain as pi-bonds i

297 ludes the biomimetic and organometallic Fe-C sigma bond, which enables bidirectional activity reminis

298 ilyl ligand is a good pai-acceptor and forms sigma-bonds with a high degree of s character.

299 B)>Ru metalacycle is formed by two bent B-Ru sigma-bonds with the concomitant increase of the bond or

300 nitrogen atom into neighboring electron-poor sigma bonds, with the seven-membered catalyst achieving