Highly diastereoselective synthesis of arylglycine derivatives via TFA-promoted Friedel–Crafts reactions of phenols with cyclic glyoxylate imines
作者:Yong-Jun Chen、Fei Lei、Li Liu、Dong Wang
DOI:10.1016/s0040-4020(03)01142-6
日期:2003.9
Optically active α-arylglycine derivatives were synthesized by Brønsted acid (TFA)-promoted Friedel–Crafts reaction of various phenols with chiral cyclic glyoxylate imines (2a–c), followed by deprotection with Pd(OH)2/C under H2. The diastereoselectivities of the initially formed F–C reaction products are up to 99%.
Lewis Acid-Catalyzed Asymmetric Diels–Alder Reactions Using Chiral Sulfoxide Ligands: Chiral 2-(Arylsulfinylmethyl)-1,3-oxazoline Derivatives
作者:Kazuhiro Watanabe、Takashi Hirasawa、Kunio Hiroi
DOI:10.1248/cpb.50.372
日期:——
New chiral sulfoxide-1,3-oxazoline ligands have been developed as chiral ligands for Lewis acid-catalyzed asymmetric Diels-Alder reactions. The use of chiral sulfinyl 1,3-oxazoline ligands in copper(II)-catalyzed asymmetric Diels-Alder reactions provided an endo cycloadduct as a major product with moderate enantioselectivity. A rationale is proposed for the mechanism of the asymmetric induction.