NCI analysis of the 2a/1c complexes
(global
minima) showing weak dispersive interactions (green surfaces) and
an attractive strong hydrogen bridge between imine and catalyst (blue
surfaces). (a) Type I E shows CH−π interaction
between the p-methyl substituent of the imine and
BINOL of the catalyst. (b) The imine is rotated 180° in Type II E and shows the aniline moiety lies on top of the
BINOL aromatic surface and the p-methyl group faces
outward from the catalyst. (c) ) In Type I Z, the
imine is also rotated and exhibits a CH−π interaction
between the α-methyl group and BINOL. (d) Similar to Type II E, Type II Z shows a π−π
interaction between the aniline moiety and BINOL, as well as a CH−π
interaction between the α-methyl group with the 2,4,6-triisopropylphenyl
group of the catalyst; For comparison and clarity, a similar orientation
as in Figure 3b was
adopted. Isovalue 0.5 and a color range between −3.0 and 3.0
were chosen.