Enantioselective addition of phenylacetylene to aldehydes catalyzed by polymer-supported titanium(IV) complexes of beta-hydroxy amides.
A series of polymer-supported chiral beta-hydroxy amides and C(2)-symmetric beta-hydroxy amides have been synthesized and successfully used for the enantioselective addition of phenylacetylene to aldehydes. High yields (up to 93%) and enantioselectivities (up to 92% ee) were achieved by using polymer-supported chiral beta-hydroxy amide 4b. The resin 4b is reused four times, giving the product with enantioselectivity 80% ee. Fortunately, it is found that this heterogenous system is suitable not only for aromatic aldehydes but also aliphatic aldehyde.
Hui
Xin-Ping
XP
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China. huixp@lzu.edu.cn
Huang
Lu-Ning
LN
Li
Ya-Min
YM
Wang
Ren-Lin
RL
Xu
Peng-Fei
PF