ライフサイエンスコーパス: hyperconjugative

1 ed in terms of the divergent contribution of hyperconjugative activation and deactivating electronic

2 onalized on the basis of a reduced extent of hyperconjugative activation associated to the greater fl

3 Here we report that hyperconjugative and steric tuning provide a new class o

4 The roles of inductive, negative hyperconjugative, and resonance electron-donation by flu

5 Electrostatic interactions, rather than a hyperconjugative anomeric effect, appear to be responsib

6 From this perspective, hyperconjugative anomeric interactions play a unique rol

7 reactivities result from differences in the hyperconjugative aromaticities and antiaromaticities of

8 mplements an earlier inference of "positive" hyperconjugative aromaticity for the cyclohexadienyl cat

9 The present work investigated whether hyperconjugative assistance and H-bonding can be combine

10 h 1,4- and 1,5-isomers can be stabilized via hyperconjugative assistance for the C...N bond formation

11 When the hyperconjugative assistance is maximized by the antiperi

12 both 1,4- and 1,5-isomers is facilitated via hyperconjugative assistance to alkyne bending and C...N

13 Optimization of hyperconjugative assistance, provided by the antiperipla

14 re constrained close to proper alignment for hyperconjugative assistance.

15 ys, ranging from aromatic stabilization to a hyperconjugative beta-Si effect.

16 ombination of C-H anion hydrogen bonding and hyperconjugative charge delocalization explains the sens

17 en decomposed into the electrostatic, steric hyperconjugative contributions to reaction barriers by u

18 Calculated pairwise-steric and hyperconjugative-delocalization energies provide a means

19 ng nitrogen atoms and maximize the favorable hyperconjugative donation from each nitrogen atom into n

20 The n(C) o*(C-X, X = F, Cl, Br) hyperconjugative effect leads to a broader shoulder regi

21 ned result of the steric effect H-8a and the hyperconjugative effect of the *C-O to the incoming 1,3-

22 al allyl ethers and emphasizes a stabilizing hyperconjugative effect, which we have termed a transiti

23 Kinetic studies suggest that hyperconjugative effects and through-space electrostatic

24 lar, polarizability, solvation, and negative hyperconjugative effects are all of some importance in p

25 ay structure analysis provides evidence that hyperconjugative effects are responsible for a change in

26 eoretical decomposition of electrostatic and hyperconjugative effects by natural bond orbital analysi

27 rmational preferences, which are dictated by hyperconjugative effects from axial substituents, with F

28 terest in the anomeric effect, anomeric-like hyperconjugative effects have been thoroughly investigat

29 ne should bear in mind that the magnitude of hyperconjugative effects is extremely sensitive to small

30 this case, can be rationalized by steric and hyperconjugative effects.

31 The polarity reversal and hyperconjugative influences have received little or no a

32 In general, the strength of the hyperconjugative interaction between the occupied sigma(

33 This effect was explained by a stabilizing hyperconjugative interaction between the sigma* orbitals

34 evel led to a conformation consistent with a hyperconjugative interaction between the vacant p-orbita

35 , as the electron donor orbital in the above hyperconjugative interaction does not exist.

36 It is traced to the hyperconjugative interaction from the oxygen lone pairs

37 d lengthening" due to n(Y)-->sigma(H[bond]X) hyperconjugative interaction is balanced by "X[bond]H bo

38 When the hyperconjugative interaction is weak and the X-hybrid or

39 tionalization of this phenomenon by negative hyperconjugative interaction of the trityl group with th

40 ration as the C-CH(3) group is involved in a hyperconjugative interaction with the empty p orbital an

41 (S) orbitals and energy of the corresponding hyperconjugative interaction.

42 Natural Bond Orbital (NBO) analysis revealed hyperconjugative interactions (E(2)) and provided insigh

43 These hyperconjugative interactions are manifested as a strong

44 The results provide strong evidence that hyperconjugative interactions are not responsible for th

45 n state of the metal and can be explained by hyperconjugative interactions between endocyclic heteroa

46 ates is associated with specific stabilizing hyperconjugative interactions between the incipient carb

47 nal difluoro motif that manifest stabilizing hyperconjugative interactions consistent with the stereo

48 sity functional theory calculations indicate hyperconjugative interactions from the beta-silyl groups

49 The interplay of steric repulsion and hyperconjugative interactions in aza-glycine's backbone

50 esults show that although there are stronger hyperconjugative interactions in the staggered anti and

51 istent with favorable sigmaC-H --> sigma*C-O hyperconjugative interactions increasing with greater or

52 The balance of hyperconjugative interactions involving C-H(ax) and C-H(

53 a-acceptors into the optimal arrangement for hyperconjugative interactions may alleviate a portion of

54 Although AE is generally attributed to hyperconjugative interactions of o-acceptors with a lone

55 C-C bonds can be overshadowed by cooperative hyperconjugative interactions with participation of remo

56 e (PES) toward the retention products due to hyperconjugative interactions.

57 F) --> sigma*(C-Y)gem, where Y = H, C, O, S, hyperconjugative interactions; that is, contrary to comm

58 oyed the BLW method to probe the electronic (hyperconjugative) interactions.

59 otope effects in 2-propanol strongly imply a hyperconjugative mechanism for the isotope effects at H1

60 We show that the complete hyperconjugative model remains superior in explaining th

61 ic assistance to the C-C bond cleavage via a hyperconjugative n(N) --> sigma*(C-C) interaction.

62 l dialkyl amine are attributed to the strong hyperconjugative n(N) o*(C-O) interaction with the two a

63 ls which are essential to make operative the hyperconjugative nature of these effects.

64 e medium-sized rings decreases the extent of hyperconjugative overlap between the alpha-C-H bonds and

65 nds that are alpha to nitrogen, activated by hyperconjugative overlap with the N-C=O pai system.

66 of the stabilization of the enol tautomer by hyperconjugative pai -> sigma*(CF) interactions and the

67 nalities, outline variations in the possible hyperconjugative patterns, and showcase the vast implica

68 romaticity to weak intra- and intermolecular hyperconjugative phenomena.

69 r "analog", the physical picture of enhanced hyperconjugative (resonance-type) delocalization in Si-O

70 e influences from the selected substituents: hyperconjugative, resonance, and electrostatic effects.

71 More generally, the hyperconjugative ring current in a family of C(2v) plana

72 Hyperconjugative sigma to sigma delocalization interacti

73 the transition state, it is argued that both hyperconjugative stabilization and inductive effects of

74 on appears to be largely offset by a loss of hyperconjugative stabilization from the adjacent C-H bon

75 a three-membered ring, the magnitude of the hyperconjugative stabilization in all other substituted

76 m is relatively shallow and that the current hyperconjugative stabilization model is inconsistent wit

77 alation faster than those that do because of hyperconjugative stabilization of the arene transfer tra

78 static effects, this analysis indicates that hyperconjugative stabilization through sigmaCC -->sigma*

79 Hyperconjugative, steric, and electrostatic effects were

80 with concomitant differences in n --> sigma* hyperconjugative transfer from O2 to CH2.

81 otope effect at H1 is due to n(p) --> sigma* hyperconjugative transfer from O5 to the axial C1--H1 bo