ライフサイエンスコーパス: pericyclic

1 , if any, are pseudopericyclic as opposed to pericyclic.

2 e 13 --> 14 and 15 --> 16 rearrangements are pericyclic.

3 ement over whether it is pseudopericyclic or pericyclic.

4 oat-shaped geometry expected for classically pericyclic [3,3] sigmatropic rearrangements.

5 A clear differentiation between a purely pericyclic and a purely pseudopericyclic mechanism is es

6 The relative positions of the bis-pericyclic and Claisen rearrangement transition states m

7 t the line between the recently proposed bis-pericyclic and Diels-Alder routes is blurred, and favora

8 It is further argued that when both pericyclic and pseudopericyclic orbital topologies are a

9 emipseudopericyclic" (halfway between purely pericyclic and purely pseudopericyclic).

10 onclusions that the 5 --> 6 rearrangement is pericyclic and that the 15 --> 16 rearrangement is pseud

11 imilar [3,3] sigmatropic rearrangements (all pericyclic), and detailed rationales for these latest re

12 beta-eliminations have been suggested to be pericyclic, B3LYP/6-31G(d,p), MP2 and MP4 calculations s

13 We expect that more pericyclic biosynthetic enzymatic transformations remain

14 e initial benzannulation step proceeds via a pericyclic cascade mechanism triggered by thermal or pho

15 rall transformation proceeds via a two-stage pericyclic cascade mechanism.

16 e derivatives are described that proceed via pericyclic cascade mechanisms featuring the participatio

17 dehydes has led to accidental discoveries of pericyclic cascade reactions that produce Z-alpha,beta-u

18 elta-unsaturated amides, a thermally induced pericyclic cascade rearrangement that converts Zincke al

19 lectrocyclic ring-opening/hetero-Diels-Alder pericyclic cascade.

20 anation of the range of pseudopericyclic and pericyclic characters found in related reactions.

21 have been unified at one time by underlying pericyclic chemistry.

22 yclic geometries are argued to reflect small pericyclic contributions.

23 On the potential energy surface, the bis-pericyclic cycloaddition transition state is followed by

24 The reactions include pericyclic, cycloaromatization, radical cyclization and

25 t in the cells surrounding primary xylem and pericyclic fibers in N. sylvestris.

26 The mechanisms of a variety of thermal pericyclic fragmentation reactions of five-membered hete

27 lied to natural product synthesis, including pericyclic, heteroatom-mediated, cationic, metal-catalyz

28 er)(CBS-QB3(0K)) = 19.0 kcal/mol) is not bis-pericyclic, leading to nondegenerate primary and seconda

29 ett principle, however, reveals that the bis-pericyclic mechanism accounts for approximately 83% of t

30 that, by using suitable functional groups, a pericyclic mechanism can be converted into a pseudoperic

31 re-to-valence spectroscopic signature of the pericyclic minimum observed in the experiment was charac

32 mediate excited-state minimum (the so-called pericyclic minimum), which leads to isomerization via no

33 d hence the process is likely neither purely pericyclic nor pseudopericyclic.

34 ns of conjugated allenes or ketenes follow a pericyclic or a pseudopericyclic mechanism has triggered

35 Aborting the pericyclic path facilitates trapping of cyclic intermedi

36 emplated electrocyclic ring-opening, but the pericyclic pathway is predicted to dominate for more ela

37 nyl)triazenes is proposed to occur through a pericyclic pathway.

38 ompetition between concerted and interrupted pericyclic pathways can be finely tuned via a combinatio

39 ght into the factors influencing the various pericyclic pathways operative in this system.

40 The ene reaction is a pericyclic process in which an alkene with an allylic hy

41 However, this reaction is not a pericyclic process; the stereoselectivity is probably of

42 s of nitroalkenes is described in which both pericyclic processes are intramolecular.

43 ategy is described based on a cascade of two pericyclic processes.

44 ps can be formulated as oxyanion-accelerated pericyclic processes.

45 3 with a rate approaching that of a related pericyclic reaction catalysed by the enzyme chorismate m

46 This nonenzymatic pericyclic reaction is considered to be biomimetic.

47 Enzymatic systems that exploit pericyclic reaction mechanisms are rare.

48 structure representations, in tautomers and pericyclic reaction partners in which only one compound

49 that catalyses an oxy-Cope rearrangement, a pericyclic reaction that belongs to a well studied and w

50 re suggests that the antibody catalyzes this pericyclic reaction through a combination of packing and

51 We contrast here examples of pericyclic reaction transition structures (where aromati

52 The combination of this pericyclic reaction with a catalytic metathesis reaction

53 dienes which will be involved in the second pericyclic reaction with juglone to construct the tetrac

54 rate Cope rearrangement of semibullvalene, a pericyclic reaction, is used as an example to visually i

55 byU active site to facilitate a transannular pericyclic reaction.

56 nto substituent effects of this prototype of pericyclic reaction.

57 nificant) with those for illustrative pseudo-pericyclic reactions (where aromaticity is less or not i

58 cade process proceeds via a sequence of four pericyclic reactions and furnishes a multiply substitute

59 ard-Hoffmann rules predict whether concerted pericyclic reactions are allowed or forbidden based on t

60 e lines of a biosynthetic proposal involving pericyclic reactions as key steps.

61 tions supported the possibility of transient pericyclic reactions as part of the isomerization-signal

62 Pericyclic reactions bypass high-energy reactive interme

63 ported examples of transition metal-mediated pericyclic reactions have been shown to proceed by nonpe

64 Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions in a single active site.

65 aerugionsa (PchB) achieves catalysis of both pericyclic reactions in part by the stabilization of rea

66 Despite the prominence of pericyclic reactions in total synthesis, only three natu

67 The rules for allowable pericyclic reactions indicate that the photoisomerizatio

68 molecular basis of catalysis among enzymatic pericyclic reactions is a matter of debate, one view hol

69 mation and bond breaking that is typical for pericyclic reactions is lost in their mechanistic cousin

70 Non-pericyclic reactions may also have aromatic transition s

71 Knoevenagel chemistry and pericyclic reactions meet again to expand the polyene-ca

72 lk rearrangements of BCP, BCN, and DCBCN are pericyclic reactions occurring with a strong preference

73 d ynamides proceeds via a cascade of several pericyclic reactions to generate multiply substituted an

74 with ynamides proceeds via a cascade of four pericyclic reactions to produce multiply substituted ani

75 The conceptual dehydrogenation of pericyclic reactions yields dehydropericyclic processes,

76 Similar to pericyclic reactions, an electron count can be used to p

77 Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions, demonstrating the eponymous activi

78 a-c into [8]AGNR occurs via a series of Hopf pericyclic reactions, followed by aromatization reaction

79 r concerted reactions, such as S(N)2, E2, or pericyclic reactions, in such a way that atoms are invol

80 ly the XP-PCM method to a selection of other pericyclic reactions, including the parent Diels-Alder c

81 Olefin chemistry, through pericyclic reactions, polymerizations, oxidations, or re

82 Pericyclic reactions-which proceed in a concerted fashio

83 is a fundamental prototype of photochemical pericyclic reactions.

84 nchronous bond formation and breaking during pericyclic reactions.

85 estabilized 1-azapentadienium ions and their pericyclic reactions.

86 ective than bulk water for catalysis of such pericyclic reactions.

87 E. coli chorismate mutase (CM) catalyzes the pericyclic rearrangement of chorismate to prephenate.

88 ion states are characteristic of a concerted pericyclic rearrangement.

89 ry can also be applied successfully to other pericyclic shifts such as [1,5]-shifts which involve chl

90 migration of two hydrogen atoms/groups in a pericyclic [sigma2s + sigma2s + pi2s] reaction through s

91 his way the bond cleavage is promoted by the pericyclic stabilization of the [2,3] transition state.

92 ce involves (1) consecutive but not combined pericyclic steps, a coarctate TS, and pseudopericyclic m

93 the 3 --> 4 electrocyclization (essentially pericyclic), the 11 --> 12 [3,3] sigmatropic rearrangeme

94 propriately aligned in an exo orientation, a pericyclic three-bond cleavage occurs.

95 tereoselective dehydration followed by three pericyclic transformations: intramolecular Diels-Alder a

96 nsition states is contrasted with the single pericyclic transition state (15TS) for the electrocyclic

97 ly affects the branching ratio after the bis-pericyclic transition state and ultimately reverses the

98 t a majority of downhill paths after the bis-pericyclic transition state lead to the Diels-Alder cycl

99 studies suggest that neither a six-membered pericyclic transition state nor any multibond concerted

100 cases, only a single highly asynchronous bis-pericyclic transition state yielding both Diels-Alder an

101 This can be rationalized by invoking a bis-pericyclic transition state.

102 nd an electron-deficient alkene via a single pericyclic transition state.

103 ransition states appear when two independent pericyclic transition states merge into one.

104 n the opposite direction compared to the bis-pericyclic transition states.

105 an aborted [3,3] sigmatropic shift where the pericyclic "transition state" becomes the most stable sp

106 and 19 --> 20 rearrangements are classically pericyclic, whereas the 15 --> 16 rearrangement is pseud