Theoretical study on the interconversion of X-benzenes （ X=Ge 、 Sn ） and

their non-aromatic isomers via the [1,3]-substituent shift: Interpaly of aromaticity

and Bent's rule

Speaker: Xuerui WangAdvisor : Jun Zhu

Dec. 27. 2013

Outline

11

3

Background

2

2

3 Summary and Future work

Results and Discussion

3

Background

Interpaly of aromaticity and Bent's rule

SiSiOR

X OXR

X = H, NMe2, F, OMe, Cl, SMe, Me, GeH3, SiH3, AlH2

Set A: R = SiH3Set B: R = Me

Figure 2. The plot of s character of Si to the Si-X σ bond vs reaction barriers (ΔG)

Figure 1.The plot of s character of Si to the Si-X σ bond vs reaction energies(ΔG)

4

Background

examine the scope of our findingsSilabenzene

(X) ΔG ΔG' ΔG'-ΔG

A1' (H)A2' (NMe2)

-0.346.8

27.674.8

27.928.0

A3' (Me)A4' (SMe)A5' (Cl)A6' (OMe)A7' (F)A8' (GeH3)A9' (SiH3)A10' (AlH2)

B1' (H)B2' (NMe2)

B3' (Me)B4' (SMe)B5' (Cl)B6' (OMe)B7' (F)B8' (GeH3)B9' (SiH3)B10' (AlH2)

17.838.177.284.8117.8-0.8-16.1-29.32.354.522.342.481.590.2122.20.1-14.8-28.5

46.167.0105.9114.0147.426.812.5-2.232.983.951.173.3114.1121.8153.830.015.6-0.2

28.328.928.729.229.627.628.631.530.629.428.830.932.631.631.629.930.428.7

aromaticity can be evaluated quantitatively

5

BackgroundHistory of Germabenzenes

1. 1980 Märkl et al. confirmed the existence of 1,4-di-tert -butyl-germabenzene indirectly supported by the formation of its [2 + 2] dimer and the trapping reaction with 2,3-dimethyl-1,3-butadiene1.

2. 1982 Spectroscopic detection of 1,4-dialkylgermabenzenes2.

3. 2002 First stable germabenzene3.

1. G. Märkl, D. Rudnick, Tetrahedron Lett. 1980, 21, 1405.2. G. Märkl, D. Rudnick, R. Schulz, A. Schweig, Angew. Chem.1982, 94, 211; Angew. Chem. Int. Ed. Engl. 1982, 21, 221.

4. N. Nakata, N. Takeda, N. Tokitoh, J. Am. Chem. Soc. 2002, 124, 6914.

6

Computational detail

Package :

Method :

Basis sets :

Gaussian 09

M06-2X

6-311+G ** ( C 、 H 、 O 、 Si 、 Ge)

aug-cc-pVTZ-PP ( Sn )

1.(a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (b) Miehlich, B.; Savin, A.; Stoll, H.; Preuss, H. Chem. Phys. Lett. 1989, 157, 200. (c) Lee, C.; Yang, W.; Parr, G. Phys. ReV. B 1988, 37, 785. 2. Zhao, Y.; Truhlar, D. G. Theor. Chem. Acc. 2008, 120, 215.3. Frisch, M. J. et al. Gaussian, Inc., Wallingford CT, 2010.

Background stable and neutral stanna aromatic compounds

7

Results and Discussion

Figure 3.The plot of s character of Ge to the Ge-X σ bond vs reaction energies(ΔG)

GeOX

RGe

OXRG

8

Results and Discussion

Figure 4.The plot of s character of Ge to the Ge-X σ bond vs reaction energies(ΔG) in nonaromatic system

Silabenzene (X) ΔG ΔG' ΔG'-ΔG

A1' (H)A2' (NMe2)

1.338.2

28.366.9

27.028.7

A3' (Me)A4' (SMe)A5' (Cl)A6' (OMe)A7' (F)A8' (GeH3)A9' (SiH3)A10' (AlH2)

B1' (H)B2' (NMe2)

B3' (Me)B4' (SMe)B5' (Cl)B6' (OMe)B8' (GeH3)B9' (SiH3)B10' (AlH2)

17.437.376.473.3106.43.0-12.0-23.42.844.621.542.880.177.64.8-10.2-23.5

43.266.0106.4102.1135.530.417.1-334.174.749.273.3112.3109.634.518.56.3

25.828.730.028.829.127.429.120.431.330.127.730.532.232.029.728.729.8

GeOX

RGe

OXRG

28.6

9

Results and Discussion

Figure 5.The plot of s character of Sn to the Sn-X σ bond vs reaction energies(ΔG)

SnOX

RSn

OXRG

10

Results and Discussion

SnOX

RSn

OXRG

Figure 6.The plot of s character of Sn to the Sn-X σ bond vs reaction energies(ΔG) in nanaromatic system

aromaticity can not be evaluated quantitatively

Si

[Os]G

OXR

Si

[Os]

OXR

11Figure 8. Plot of reaction free energies (ΔG) against the percentage of the s character of Si in the Si-X bonds in the osmasilabenznes.

Results and Discussion

12

Results and Discussion

nme 45. 1 76. 6 31. 5sme 39. 4 72. 9 33. 5me 16. 6 47. 8 31. 2h -3. 6 24. 3 27. 9ge -10. 1 28. 7 38. 8si -18. 5 18. 4 36. 9al -19. 9 6. 4 26. 3

me 12. 6 50. 1 37. 5h -6. 3 28. 6 34. 9ge -14. 6 24. 3 38. 9si -23. 1 13. 7 36. 8al -24. 5 -2. 7 21. 8nme 44. 6 82. 2 37. 6

R=SiH3 ΔG ΔG' ΔG'-ΔG

R=Me ΔG ΔG' ΔG'-ΔG

33.4

Figure 9. Plot of reaction free energies (ΔG) against the percentage of the s character of Si in the Si-X bonds .

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1. The contribution from aromaticity can be evaluated

quantitatively in such rearrangement .

2. Bent's rule plays an important role in both the

thermodynamics and kinetics of the rearrangement .

3. Our findings could be a useful guide to the synthesis of

X-benzenes (X = Ge 、 Sn).

Summary

14

Organophosphorus

compounds

14

pesticide

flame retardant

medicine

antibacterial agents

enzyme inhibitors

anti HIV agents

Experiments

？P

OEtO

EtOH

P

OEtO

EtO

15

Entry initiator eq solvent T(oC) t[h]NMR yield

[%]

1 Mn(OAc)3 2.2 HOAc 80 12 15

2 Mn(OAc)3 2.2 DMF 80 12 5

3 Mn(OAc)3 2.2 THF 80 12 trace

4 AgNO3 0.5 DMF 80 12 trace

5 AIBN 1.2 THF 80 12 trace

Condition Optimization

16

PO

OEt

EtO

Et2OP

O

Et2OP

O

Mn3+

Mn2+

Et2OP

O

+

- H+

HPO

OEt

EtO

Mn3+

Mn2+

Et2OP

O

Proposed Reaction Mechanism

17

PO

OEt

EtO

Et2OP

O

Mn3+

Mn2+

Et2OP

O

AcO-

Et2OP

O

OAc By product

1. Yang et al, Angew. Chem. Int. Ed. 2013, 52, 3972.2. Zou et al, Synthesis 2013, 45, 1529 .

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