TARTROL-derived chiral phosphine–phosphite ligands and their performance in enantioselective Cu-catalyzed 1,4-addition reactions
作者:Mehmet Dindaroğlu、Sema Akyol、Hamza Şimşir、Jörg-Martin Neudörfl、Anthony Burke、Hans-Günther Schmalz
DOI:10.1016/j.tetasy.2013.04.008
日期:2013.6
(with a 1,2-phenylene backbone) were synthesized and evaluated in the Cu-catalyzed asymmetric 1,4-addition of Grignard reagents to cyclohexenone. Ligands with bulky substituents at the ortho- and para-positions to the chiral phosphite moiety were found to be the most selective affording the 1,4-addition products with enantioselectivities of up to 84% ee.
通过使用(R,R,R,R)-2,3-二甲氧基-2,3-二甲基-1,4-二恶烷-5,6-双二联苯甲醇(TARTROL)作为手性结构单元,一组六合成了模块化的膦-亚磷酸酯配体(具有1,2-亚苯基骨架),并在Cu催化的格氏试剂与环己烯酮的不对称1,4-加成反应中进行了评估。发现在手性亚磷酸酯部分的邻位和对位具有大的取代基的配体是最具有选择性的,提供对映选择性高达84%ee的1,4-加成产物。