ライフサイエンスコーパス: homolysis

1 ex, which is therefore nicely set up for O-O homolysis.

2 ich to investigate the mechanism of coenzyme homolysis.

3 bon-carbon activation and carbon-oxygen bond homolysis.

4 nd a crossing to the LS surface for O-O bond homolysis.

5 isms by which the Co-C bond is activated for homolysis.

6 The synthesis by Ln(III)-A homolysis allows [5f(1)-4f(n)]2 and Li[5f(1)-4f(n)] comp

7 adiation of 9 led principally via SO2-N bond homolysis and [1,5] sigmatropic rearrangement to generat

8 Ph, it was shown that C-O cleavage occurs by homolysis and by 1,2-elimination in a ratio of 1.4:1, re

9 ls and differences in mechanisms of O-O bond homolysis and electrophilic H-atom abstraction reactions

10 e of substrate, catalyzes carbon-cobalt bond homolysis and formation of a thiyl radical from an activ

11 denitroxylation) of the nitrite via O-N bond homolysis and H-abstraction from the resultant benzyloxy

12 We conclude that homolysis and heterolysis of the dioxygen bond with form

13 H bond, of which the most widespread are M-H homolysis and R-H reductive elimination.

14 stribution of prototropic isomers in driving homolysis and stabilizing radical intermediate states is

15 nal aldimine and elicit the AdoCbl Co-C bond homolysis and the accumulations of cob(II)alamin and ana

16 2-thiolglutarate elicits cobalt-carbon bond homolysis and the formation of 5'-deoxyadenosine.

17 spect to wt-RTPR-mediated carbon cobalt bond homolysis and the intermediacy of the 5'-deoxyadenosyl r

18 he enzyme-bound state, the RP generated upon homolysis appears to be stabilized against the extent of

19 nt effects point to heterolysis, rather than homolysis, as the step that breaks the S-O bond.

20 lallenes racemize by reversible thermal bond homolysis at 95 degrees C; racemization of these metalla

21 lower the kinetic barrier to bimetallic O(2) homolysis at five-coordinate oxorhenium(V) by facilitati

22 ied before are much less suited for O-O bond homolysis, because the resulting Cu(III)=O species is le

23 Together, these results are consistent with homolysis becoming completely rate determining in the fo

24 rvation is consistent with adenosylcobalamin homolysis being slowed relative to hydrogen abstraction

25 CoA mutase accelerates the rate of Co-C bond homolysis by a factor of approximately 10(12).

26 ly that redox-active ligands facilitate O(2) homolysis by lowering the barrier to the formally spin-f

27 ransfer to the iron center subsequent to C-H homolysis competes with ring-opening in the processing o

28 those alkoxyamines that decompose by the N-O homolysis/disproportionation pathway are much less effec

29 that correlates with (2)A(1) lowers the O-O homolysis energy by approximately 15 kcal/mol, similar t

30 ed mechanism hypothesized to involve a Ni-Br homolysis event from an excited-state nickel complex.

31 bstrates and diphenylamines decompose by N-O homolysis followed by disproportionation.

32 complex, Cr(aq)OONO(2+), undergoes O-O bond homolysis followed by some known and some novel chemistr

33 f the Co-C bonds is much more favorable than homolysis (>21 kcal/mol) and is significantly more exerg

34 ddition, the reaction coordinate of the Fe-O homolysis has been investigated, which is a possible dec

35 of the sulfonamide linkage to excited-state homolysis holds comparative interest.

36 The C-ON bond homolysis in alkoxyamine 2a was chemically triggered by

37 The C-ON bond homolysis in alkoxyamines can be influenced by the prese

38 roxide played an important role in C-ON bond homolysis in alkoxyamines.

39 to contact ion pairs following photoinduced homolysis in solution is studied using picosecond pump-p

40 hat the resulting Ni-C bond does not undergo homolysis in subsequent stages of the catalytic cycle.

41 l-oxo intermediate stability enables the O-O homolysis in the case of iron but directs the copper com

42 elerates O(2) binding and minimizes O-O bond homolysis in the reduction of H(2)O(2).

43 Direct measurements of the rate of Ti-O bond homolysis in Ti-TEMPO complexes Cp2TiCl(TEMPO) (3) and C

44 These results suggest that Co-C bond homolysis is coupled to hydrogen atom abstraction from t

45 )](x)(+) and the reaction coordinate for O-O homolysis is explored for both the low-spin and the high

46 The O-O bond homolysis is found to be endothermic by only 15 to 20 kc

47 This implies a mechanism in which Co-C bond homolysis is kinetically coupled to substrate hydrogen a

48 ate that the energy of the Calpha Cbeta bond homolysis is predominantly affected by the stability of

49 th deuterated substrates; this suggests that homolysis is slowed relative to hydrogen abstraction by

50 s generated through photochemical Ts-Br bond homolysis lead to the formation of cyclic dibromide side

51 ermolysis of the complex results in N-O bond homolysis, leading to the formation of an iron(III) oxo

52 escape of the alkoxyl radicals following N-O homolysis leads to significantly less effective regenera

53 Significantly, this soft homolysis mechanism provides a method to generate closed

54 t with the calculations for the H-bonded O-O homolysis mechanism.

55 stopped-flow kinetic measurements of AdoCbl homolysis obtained with deuterated substrates.

56 of fac-[Re(dmb)(CO)(3)(CH(3)CN)]PF(6) or by homolysis of [Re(dmb)(CO)(3)](2).

57 sulfinyl radical (X-Cys SO .-Y) ions through homolysis of a Calpha Cbeta bond.

58 II)(A)3 (A = N(SiMe3)2, OC6H3Bu(t)2-2,6) via homolysis of a Ln-A bond.

59 nism involving decarbonylation and Ni-C bond homolysis of a Ni(II) adduct is proposed.

60 ological redox processes, enables the formal homolysis of a stronger amide N-H bond in the presence o

61 r 4, consistent with a process involving the homolysis of a weak Ti-O bond to generate the transient

62 on the ability of the enzyme to catalyze the homolysis of adenosylcobalamin has been investigated usi

63 yleneglutarate to glutamate mutase initiates homolysis of adenosylcobalamin.

64 s revealed that L-2-hydroxyglutarate-induced homolysis of AdoCbl occurs very rapidly, with a rate con

65 t k(d) of the chemically activated C-ON bond homolysis of alkoxyamines was subject to solvent effects

66 major photoproduct channels corresponding to homolysis of aryl-OO and arylO-O bonds resulting in loss

67 Homolysis of C1-C8 to give a conformationally flexible d

68 The O-O bond homolysis of cis,cis-ONOONO is particularly interesting

69 aks down to release NO more readily than via homolysis of GSNO.

70 The homolysis of I(O) is much favored over that of the neutr

71 mol) in the rate-determining step, i.e., the homolysis of I2k, agreed well with the experimental valu

72 the spin state changes to triplet during the homolysis of I2k; in this way two malonyl radicals are f

73 and introduce SO(4)(-*), generated by 248 nm homolysis of low millimolar levels of persulfate, as a r

74 The homolysis of O-O bond produces NO(2) and L(2)(H(2)O)RhO(

75 -migration mechanism of deamination-and that homolysis of SAM concomitant with H atom abstraction fro

76 -adenosylmethionine (SAM) enzyme, catalyzing homolysis of SAM to 5'-deoxyadenosine (5'-dAdo) in the p

77 -2,4-diaminobutryic acid (DAB) induces rapid homolysis of the AdoCbl Co-C bond (781 s(-1), D-ornithin

78 orresponding imidazolium salts mainly caused homolysis of the ArO-S bond.

79 Methoxy substituents enhance the homolysis of the beta-O-4 linkage, relative to PPE, in o

80 nzo[ghi]fluoranthene as the major product by homolysis of the C-Cl bond, 1,4-shift of a hydrogen atom

81 alkyl fragment was suitable to activate the homolysis of the C-ON bond.

82 his exchange reaction in which RNR catalyzes homolysis of the carbon-cobalt bond in a concerted fashi

83 B12-dependent reactions, is postulated to be homolysis of the Co-C bond of the cofactor.

84 rate that the enzyme accelerates the rate of homolysis of the cobalt-carbon bond by at least 10(12)-f

85 ing further support for a mechanism in which homolysis of the coenzyme is coupled to hydrogen abstrac

86 It was found that homolysis of the coenzyme is slower by an order of magni

87 pparent rate constants for substrate-induced homolysis of the coenzyme that are slower by 7-fold and

88 terium isotope effects that are observed for homolysis of the coenzyme when the wild-type enzyme is r

89 y use substrate binding energy to accelerate homolysis of the coenzyme.

90 )(CO)2Os(*) radicals, formed by photoinduced homolysis of the corresponding osmium dimers.

91 IX2 (X = (pseudo)halide), that undergo rapid homolysis of the hypervalent I-X bonds and generate (pse

92 oducts (ca. 20 mol %) are also formed by C-O homolysis of the methoxy group.

93 First, homolysis of the N-OH bond in 2 may yield the well-known

94 s by ONOOH and NO(2)(*), a radical formed by homolysis of the ONOOH bond, is unusually rapid but that

95 However, proton-assisted homolysis of the peroxo hemiacetal intermediate to produ

96 IV) (O) and (.) NO2 species through O-O bond homolysis of the peroxynitrite ligand.

97 from the OOH to the OH ligand and the other homolysis of the Pt-OOH bond, abstraction of the OH liga

98 ficantly faster than can be accounted for by homolysis of the S-N bond.

99 y EPR spectroscopy that they underwent clean homolysis of their N-O bonds upon UV photolysis.

100 glycerol but have not done so in the thermal homolysis of this bond in the enzyme-bound cofactor in t

101 of reductively generated Co(II)H rather than homolysis of two Co(III)H units.

102 oxidizing radicals derived from its O-O bond homolysis, or the other oxidants under study.

103 Surprisingly, molecule-assisted homolysis plays a key role in this transformation, the d

104 ng alphabeta absorption band results in bond homolysis proceeding via a bound cob(III)alamin MLCT sta

105 served in the spectroscopic data of the post-homolysis product Co2+ Cbl when bound to glutamate mutas

106 of the reduced B12 cofactor (i.e., the post-homolysis product Co2+ Cbl) is modulated by the enzyme m

107 ctivation involves stabilization of the post-homolysis product, Co2+ Cbl, rather than destabilization

108 O2Me)FeIII(OH) give both O-O heterolysis and homolysis products, Compound I (Cpd I) and Compound II (

109 iven the extremely fast back-reaction of the homolysis products, heterolysis probably dominates the o

110 gh enzyme-mediated stabilization of the post-homolysis products.

111 ugh stabilization of the Co(2+)Cbl/Ado. post-homolysis products.

112 The motivation to develop amide homolysis protocols stems from the utility of the result

113 ion of two kinetic parameters, the C-ON bond homolysis rate constant (kd) and its re-formation rate c

114 up (OMe, OAc, OBz, OBn, or OTBDMS), a higher homolysis rate constant k(d) is observed, as expected fr

115 ts, which leads to an 8-fold decrease in the homolysis rate constant k(d).

116 Comparison of the homolysis rate for the free and enzyme-bound cofactors r

117 trillion-fold acceleration of Co-carbon bond homolysis rate in the methylmalonyl-CoA mutase-catalyzed

118 ctrophotometry, we demonstrate that the Co-C homolysis rate in the presence of protiated substrate ha

119 ecreases their energies and enhances the O-O homolysis rate, which is consistent with the acceleratio

120 thermodynamic parameters associated with the homolysis reaction catalyzed by methylmalonyl-CoA mutase

121 The homolysis reaction of the HS [(TMC)Fe(III)-OOH](2+) comp

122 t could not be directly determined including homolysis reactions of the Rh(II)-Rh(II) dimer with wate

123 ence of CO(2), and also in the types of bond homolysis reactions that PNA and PNI may undergo.

124 proton-controlled, 2e- (heterolysis) vs 1e- (homolysis) redox specificity sheds light on the exceptio

125 )Pr2)3Co-N2 (5) via a proposed Co-alkyl bond homolysis route.

126 ad end" since the radical pairs generated by homolysis should mostly revert to starting material.

127 all the enzymes that have been examined, the homolysis step is kinetically indistinguishable from abs

128 also results in isotope effects on coenzyme homolysis that are much smaller than the very large effe

129 S of 96 cal mol-1 K-1 for carbon-cobalt bond homolysis/thiyl radical formation.

130 nds locks the HO. radical, formed by the O-O homolysis, thus directing it to exclusively abstract the

131 e-steady-state kinetics of adenosylcobalamin homolysis to be investigated by stopped-flow spectroscop

132 ce of weak C-H bonds, but decay via N-O bond homolysis to ferrous or ferric iron hydroxides in the pr

133 I(O) undergoes O-O homolysis to form a biradical Bt, which is fragmented in

134 ydrofuran as solvent, the O-O bond undergoes homolysis to generate (*)NO2 (detected spectrophotometri

135 al cation, [CpW(CO)(2)(IMes)H](*+), W-H bond homolysis to generate the 16-electron cation [CpW(CO)(2)

136 rrangement involves excited state ArO-C bond homolysis to give para-substituted phenoxyl radicals, wh

137 The weak O-N bond of 3a is susceptible to homolysis under photolysis conditions, and the radical 7

138 nostic agents by activation of the C-ON bond homolysis, we turned our interest to the chemical activa

139 d before the barrier; the other involves O-O homolysis, where the phenol remains H-bonding to the per

140 The rate of Co-C bond homolysis, while slow for the free cofactor, is accelera