title: An efficient dipeptide-catalyzed direct asymmetric aldol reaction of equimolar reactants in solid media.
abstract: The direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, moderate to high isolated yields (up to 95%), good diastereoselectivities (>99:1), and enantioselectivities (up to 98% ee) have been achieved for the reactions of different kinds of ketones with various aldehydes. The catalytic system could be reused without decrease of activity by addition of 10 mol % catalyst and base in the catalytic system.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Lei
authors.forename: Shuai
authors.initials: S
authors.lastname: Xia
authors.forename: Junfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Zemei
authors.initials: Z
authors.lastname: Ge
authors.forename: Tieming
authors.initials: T
authors.lastname: Cheng
authors.forename: Runtao
authors.initials: R
authors.lastname: Li
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry; D002384:Catalysis; D004151:Dipeptides / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D004151:Dipeptides; D007659:Ketones; D000537:Aluminum Oxide