化工翻译

Table 1 shows that (R,R)-1 and (S,S)-3 bind amino alcohols with the same sense of stereoselectivity. We suggest that folding of the complex is an important factor for determining the sense of the stereoselectivity. The stereoselectivity of (S,S)-3 increases from about 2.9 to 36.0 with increasing steric bulk of the amino alcohol(10 > 9 > 8). In contrast, the stereoselectivity of (R,R)-1 remains low (selectivity ≈2.6) independent of the size of the amino alcohol. Since the nitrophenyl group in 3 is much bigger than the hydrogen in 1, the binding cavity should be smaller for 3. As larger amino alcohols fill the small cavity in 3, the stereoselectivity is expectedto increase.