The title reaction was performed by ONIOM method combined with QM and MM. Structural analysis showed that the skeleton of valine deformationed obviously induced by confinement effect of SWBNNT(5

5)

at the same time SWBNNT(5

5) also had an obvious deformation. Calculation showed that the optical isomeric reaction channel with amino nitrogen as the proton transfer bridge had advantages for valine molecules. When valine molecules confined in SWBNNT(5

5)

the intrinsic energy barrier of optical isomers rate-limiting step was 318.41 kJ·mol

-1

. When proton transfer and hydroxyl rotation occurred simultaneously and stepwise

the related intrinsic energy barrier of optical isomers rate-limiting step were 306.42 and 306.93 kJ·mol

-1

in SWBNNT(6

6)

respectively

which were significantly higher than the intrinsic energy barrier of the bare reaction dominant channel with the value of 262.81 kJ·mol

-1

. When valine molecules confined in SWBNNT(7

7)

the intrinsic energy barrier of optical isomers ratelimiting step was 262.81 kJ·mol

-1

which was no different from that in the naked reaction. The results showed the confinement of SWBNNT(5

5) and SWCNT(6

6) had an obvious negative catalysis to optical isomers of valine molecules.