Asymmetric copper-catalyzed Diels-Alder reaction revisited: control of the structure of bis(oxazoline) ligands

作者：Le Maux Paul^*; Dorcet Vincent; Simonneaux Gerard

来源：Tetrahedron, 2013, 69(38): 8291-8298.

DOI：10.1016/j.tet.2013.06.093

• Chiral bis(oxazoline) synthesis
• Bicyclo[2.2.2] backbone
• Diels-Alder catalysis
• Copper
• Enantioselectivity

Synthesis of 1,4-bis(oxazoline) ligands bearing a bicyclo[2,2,2]backbone derived from 9,10-dihydro-9,10-ethanoanthacene trans-dicarboxylic acid was revisited. Starting from L- or D-amino alcohols and either (S,S) or (R,R)-dihydroethano trans-dicarboxylic acid, a complete series of ligands was evaluated in the copper-catalyzed Diels-Alder reaction. The most efficient ligands with a phenyl substituent on the oxazoline ring afforded enantiomeric excess up to 98%. This is different from previous results indicating that the best enantioselectivity involved a diastereomeric ligand with the meso-backbone.

• 出版日期2013-9-23