Lou Sha, Schaus Scott E
Department of Chemistry, Center for Chemical Methodology and Library Development, Boston University, 24 Cummington Street, Boston, Massachusetts 02215, USA.
J Am Chem Soc. 2008 Jun 4;130(22):6922-3. doi: 10.1021/ja8018934. Epub 2008 May 7.
Chiral biphenols catalyze the enantioselective Petasis reaction of alkenyl boronates, secondary amines, and ethyl glyoxylate. The reaction requires the use of 15 mol % of (S)-VAPOL as the catalyst, alkenyl boronates as nucleophiles, ethyl glyoxylate as the aldehyde component, and 3 A molecular sieves as an additive. The chiral alpha-amino ester products are obtained in good yields (71-92%) and high enantiomeric ratios (89:11-98:2). Mechanistic investigations indicate single ligand exchange of acyclic boronate with VAPOL and tetracoordinate boronate intermediates.
手性联苯酚催化硼酸烯酯、仲胺和乙醛酸乙酯的对映选择性Petasis反应。该反应需要使用15 mol%的(S)-VAPOL作为催化剂，硼酸烯酯作为亲核试剂，乙醛酸乙酯作为醛组分，以及3A分子筛作为添加剂。手性α-氨基酯产物以良好的产率（71-92%）和高对映体比例（89:11-98:2）获得。机理研究表明无环硼酸酯与VAPOL发生单配体交换以及四配位硼酸酯中间体的形成。
